Paging system for entering pages by local telephone call

ABSTRACT

A paging network is disclosed which utilizes a plurality of distibuted switches to transmit pages on a non-real time basis to achieve efficient and low cost transmission. Each of the switches processes packets of pages received from the network. Each of the switches also processes pages into packets of pages to be transmitted to another switch in the network or into batches of pages to be transmitted by a local paging service if the switch is a local switch. The network dynamically programs the reception channel(s) of the paging receivers in response to traffic conditions of a local switch or in accordance with service options specified by a subscriber to a local paging service. The digits of the paging receiver identification code are transmitted in an order of increasing significance to conserve battery life of the paging receivers. Pages may be initiated by placing a local call to any lata switch in the network and service options may be varied by placing of a local call to a lata switch.

MICROFICHE APPENDIX

A Microfiche Appendix containing a hexadecimal code listing of theprograms used by the sublocal, local, lata and hub switch processorsused with the present invention containing 3 microfiche having a totalof 267 frames is attached hereto. The program is written in assemblylanguage of the Intel 80286 microprocessor. The Microfiche Appendixcontains subject matter which is copyrighted. A limited license isgranted to any one who requires a copy of the program disclosed thereinfor purposes of understanding or analyzing the present invention, but nolicense is granted to make a copy for any other purpose, including theloading of a computer with code in any form or language.

CROSS REFERENCE TO RELATED APPLICATIONS

Reference is made to the following United States patent applicationswhich are incorporated herein by reference in their entirety.

1. U.S. patent application Ser. No. 110,514, entitled "Paging ReceiverWith Continuously Tunable Antenna" which was filed on Oct. 20, 1987.

2. U.S. patent application Ser. No. 110,658, entitled "Paging ReceiverWith Programmable Areas of Reception" which was filed on Oct. 20, 1987.

3. U.S. patent application Ser. No. 110,511, entitled "Paging ReceiverWith Paging Receiver Identification Code Digits Transmitted In Order ofIncreasing Significance" which was filed on Oct. 20, 1987.

4. U.S. patent application Ser. No. 110,664, entitled "Paging ReceiverWith Dynamically Programmable Functionality" which was filed on Oct. 20,1987.

5. U.S. patent application Ser. No. 110,522, entitled "Paging ReceiverDisplaying Place of Origin of Pages" which was filed on Oct. 20, 1987.

6. U.S. patent application Ser. No. 110,512, entitled "Paging ReceiverFor Receiving Pages From Analog or Digital Paging Transmitters" whichwas filed on Oct. 20, 1987.

7. "Paging System" Ser. No. 158,984 filed on even date herewith.

8. "Paging System Local Switch", Ser. No. 158,716 filed on even dateherewith.

9. "Paging System Lata Switch", Ser. No. 158,937 filed on even dateherewith.

10. "Paging System Hub Switch", Ser. No. 158,524 filed on even dateherewith.

11. "Paging System With Dynamically Programmable Reception Frequencies",Ser. No. 158,931 filed on even date herewith.

12. "Paging System With Commands For Changing Functionality of a PagingReceiver", Ser. No. 158,983 filed on even date herewith.

13. "Paging System With Transmission Protocol Compatible With Analog andDigital Transmitters", Ser. No. 158,981 filed on even date herewith.

14. "Paging System Sublocal Switch", Ser. No. 158,950 filed on even dateherewith.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to paging systems.

2. Description of the Prior Art

Paging systems are in use throughout the world. There are paging systemswhich transmit pages from satellite transmitters to different cities. Anexample of such a system is that operated by National Satellite Pagingwhich transmits only pages consisting of numeric characters. A systemoperated by Metrocast transmits pages to any city within the systemthrough a serial communication link between the cities. The Metrocastsystem has a central switch which includes all of the subscriber filesand a plurality of local switches which are located in separategeographic locations that are connected together by the serialcommunication link. In the Metrocast system, pages transmitted locallyby a single paging service are exclusively made by calling into the citywhere the page is to be made by a local telephone call. A page to bemade on a regional basis involving transmission of pages between two ormore locations is called in by an 800 number telephone call to a centralfacility in San Diego from which the page is transmitted to the citywhere the page is to be broadcast by the serial communication link. Thepage is received from the communication link at the city where it is tobe broadcast and then broadcast locally by an existing paging service totransmit the page to the person to be paged. In the Metrocast system,the pages are transmitted from the central switch with an address of aswitch in a remote location which is to receive the page. All of theintermediate local switches between the central switch and the remoteswitch which is to receive the page function to relay the pages to theremote switch. The pages are transmitted in one direction along theserial communication link which functions as a loop beginning and endingat the central switch. Each intermediate switch located along the serialcommunication link removes pages which are addressed to it. However, theintermediate switches do not disassemble the pages and reassemble thepages and add pages thereto originating at the intermediate switches fortransmission to other switches along the serial communication link.

BBL Industries manufactures a digital linking module which connectsmultiple switches together to form a regional paging network. Thissystem transmits individual pages between the switches over a dedicatedcommunication link. The subscriber file is located at the switchoriginating the page. The remaining switches function only to removepages which are addressed to them and do not modify the pages. Pagesmust be originated by calling the switch with the subscriber file.

Paging systems currently in use in the United States maintain subscriberidentification information used for making pages transmitted betweenmultiple switches at a single location. In Metrocast, the central switchin San Diego stores the subscriber information in a file which includesthe destination(s) of pages for each subscriber. Local paging serviceswhich service a single area also maintain a subscriber file at a centrallocation.

Subscriber files contain a subscriber identification number which is aunique identification of the subscriber within the system, whethernational or local in nature. The subscriber identification number alsofunctions as the address of the paging receiver of the subscriber and isbroadcast with each page that is addressed to the paging receiver of thesubscriber. Furthermore, the subscriber file stores the type of servicethat each subscriber is to have provided when the paging servicereceives a request for a page. Paging systems rely on the subscriberfile to provide the information necessary to provide the type of servicethat each subscriber requires upon receipt of a request for a page anddo not require the requester of a page to know anything other than theidentification number of the party being paged and the page itself.

Currently, subscriber files do not store subscriber identificationnumbers which have a geographic significance regarding the location ofthe subscriber local paging service within an overall system. Moreover,current paging systems do not process the subscriber identificationnumber to determine a subscriber local paging service location whichstores the subscriber file of the subscriber when pages are made whichoriginate outside of the area of the subscribers' local paging service.Current paging systems do not transmit requests for pages originatingoutside the local paging service providing local service to thesubscriber to the local paging service to determine the type of serviceand the destination of the page by using the network to transmit therequest to the local paging service. To place a page from a geographicarea outside of the subscribers' local paging service area, currentsystems require an 800 type call (Metrocast) or a long-distance phonecall to be made. Current paging systems do not permit a local call to beused for originating a request for a page from outside the service areaof the local paging service, such as requesting a page in Washington,D.C., while being located in New York by making a local phone call to alocation in New York.

To date, there is no existing national paging system which substantiallycovers the geographical United States with reliable service. Because ofthe cost of hardware, a system like the Metrocast system is noteconomical in small cities or rural areas where the paging volume isrelatively low. Accordingly, while the objective of achieving nationwidepaging has been attempted for many years, no existing system integrateslocal and national paging substantially throughout the geographicalUnited States or throughout the world. The vast majority of pagingsystems operate totally locally with each system having a limitedfunctionality because of their inability to effectively deliver regionalor national (non-local) paging.

Most paging receivers are tuned to receive only a single channel whichinherently limits their usage at times when heavy paging conditionsexist in a local paging system and further prevents usage in othergeographical locations where other channels are used.

Typically, each existing paging system has unique specifications whichprevent operation of its paging receivers in other systems. For example,the paging receiver identification codes are not universal. Furthermore,existing paging receivers only receive pages from a single type oftransmitter (analog or digital). As a result of paging receiversdiffering in design and operation, the cost of paging receivers ishigher as a result of smaller manufacturing volumes than would berealized if a single paging receiver was usable for a worldwide network.

Paging services which provide a service area that is not limited to alocal paging service area (pages involving more than one switch)transmit on a single channel or cyclically on a band of closely relatedchannels.

It is estimated that 25% of the paging receivers in use in the UnitedStates are serviced by private paging systems and services (non-commoncarrier). The private municipal paging system 384, private hospitalpaging system 386, stock quote service 388, and other private systems374 illustrated in FIG. 28 are representative of the prior art privatepaging systems and services. These prior art systems and services havenot been integrated with common carrier local paging services asillustrated in accordance with the present invention in FIG. 28 or intoa paging network as illustrated in accordance with the present inventionin FIG. 1. Paging receivers encompassing both private and common carriermultiple paging frequencies have not been available to date. Thetransmitters of non-common carrier systems and services have lowerbroadcast power than the transmitters of common carrier paging systems,and therefore have a limited range in comparison with common carriersystems. As a result, there is a lack of continuity in service rangeprovided by non-common carrier systems and services when a comparison ismade to common carrier local paging services. Moreover, the lack ofcontinuity in the range of service provided by private paging systemsand services causes persons wishing to receive paging service fromcommon carriers and private non-common carrier systems and services tocarry multiple paging receivers creating at least an inconvenience forthe user and additional expense in purchasing multiple paging services.

While current paging services providing paging involving transmission ofpages between multiple switches have a distributed network of switches,they do not utilize the distributed switches to maximize the efficiencyof transmission of pages within a local service area and outside of thelocal service area. These systems control the transmission of pagesbetween switches by sorting of the pages at the originating centralswitch where the subscriber file is located. The pages are not furthersorted and packetized during their transmission at intermediate switcheslocated between the originating central switch and the destinationswitch which limits the efficiency of transmission that could beachieved by a system in which the pages at intermediate switches aresorted, buffered and combined with new pages that originate at theintermediate switches that are to be transmitted toward the destinationswitch to minimize the cost of transmission to a destination switch.Furthermore, none of these systems permits pages to be entered by thelocal switch into the switching network while bypassing the centralswitch because of the fact that subscriber information is centrallystored and must be centrally processed.

The central processing of pages by existing systems has distinctdisadvantages. First, expansion of the capacity of the network islimited by the capacity of the central switch to process all requestsfor pages. Since studies of the assignee reveal that a majority of pages(70%) originating at a local paging facility are typically intended foronly the broadcast by a single local paging facility, central processingof a page to be broadcast by a single local paging service necessarilyplaces a high processing overhead on the central processor's ability toprocess pages which are to be transmitted between switches (i.e.,non-local paging) and necessitates the making of a long-distance or 800phone call. Furthermore, the cost of expanding the capacity of a centralprocessing facility to increase the volume of pages can involvesubstantial expense. Finally, a malfunction in the central processingsystem processing the requests for pages throughout the network cancause the whole network to go down.

Each paging receiver in the Metrocast system cyclically scans aplurality of closely spaced channels to detect the presence of a pageaddressed to the paging receiver on any one of the closely spacedchannels. Paging receivers in the Metrocast system have the disadvantagethat the required continual scanning of the closely spaced channelsconsumes a substantial amount of power causing the batteries of thepaging receiver to have a short service life. Short battery lifeincreases the cost of operation of the paging receiver, can cause pagesto be lost when the batteries are not promptly replaced and caninterfere with the ability to market paging services as being"economical" given the cost of battery replacement.

There currently is no universal standard for issuing identificationnumbers to paging receivers, with the largest system having capacity forissuing only 2,000,000 paging receiver identification codes. Worldwide,there currently are over 12,000,000 paging receivers in use withprojected growth on an annual basis in the paging industry possiblyexceeding 20%. Thus, current paging systems do not permit a worldwidepaging system to be realized as a result of the actual and projectednumber of paging receivers being far larger than the capacity of theidentification codes in the largest existing paging system.

All paging receivers currently consume considerable battery power inmonitoring the one or more channels on which they are designed toreceive pages to detect if a paging receiver identification codeaccompanying a page on the one or more channels matches its storedpaging receiver identification code. If a match exists, then a page isprocessed and an alarm and a display of the message is provided by thepaging receiver of the message contained with the page. These systemstransmit the paging receiver identification code in an order ofdecreasing significance of the digits of the identification code. Inother words, if a paging receiver has the identification code 12345, thetransmitter precedes the transmission of the page which is addressed tothe paging receiver with the sequence of digits 12345. Each pagingreceiver which receives the channel on which the paging receiveridentification code is transmitted continually detects each of thesuccessive digits and maintains its radio frequency receiver tuner inany "on" state until a mismatch is found between the transmitted andstored paging receiver identification code digits. As a result of thefact that many paging receivers have the most significant digits incommon with other paging receivers within a system, a substantial amountof battery power is consumed detecting if a broadcast page is addressedto a particular paging receiver. Each paging receiver which receives thedigits of the paging receiver identification code in an order ofdecreasing significance is statistically likely to have its radiofrequency receiver turned on for most of the transmission of the digitsof the paging receiver identification code until the lesser significantdigits of the paging receiver identification code are received whichenable a final determination to be made of the paging receiver to whicha page on a frequency is addressed. The lesser significant pagingreceiver identification code digits are the digits which begin todistinguish one paging receiver from another and only the leastsignificant paging receiver identification digit distinguishes thepaging receiver which is desired to receive a particular page from allother paging receivers. Accordingly, the transmission of the pagingreceiver identification code digits in an order of decreasingsignificance substantially increases power consumption lessening thelife of the batteries of the paging receivers in a system.

Throughout the world, different frequency bands have been adopted fortransmitting pages. In the United States, transmissions are authorizedon VHF and UHF bands. In the United States, the channels of the VHF andUHF bands are separated by 5 KHz steps. Moreover, for each of thesebands in the United States, transmitters are in existence which transmitpages by frequency modulation of a digitally encoded carrier wave andother transmitters which transmit pages by frequency modulation of ananalog encoded carrier wave. Currently, no paging receiver exists whichis compatible with transmissions from both analog and digitaltransmitters. Furthermore, Europe has allocated VHF channels for pagingwith individual channel 5 being separated by 6.25 KHz steps and FarEastern countries have allocated paging frequencies on a 280 MHz VHFband with individual channels being separated by 2.5 KHz steps.Currently, paging receivers do not exist which are operational on anymore than one of the above-identified frequency bands. The inability ofcurrent paging receivers to receive pages on the different frequencybands allocated throughout the world effectively prevents worldwidepaging to be received on a single paging receiver.

None of the existing paging systems dynamically change the channels onwhich a paging receiver in the system may receive pages which severelyrestricts the paging receivers to usage in limited geographical areas.In the United States, there are a large number of paging channels in usein different geographical parts of the country. Because of the fact thatthe channel reception of existing paging receivers are not dynamicallychanged, it is impossible to universally receive pages throughout thecountry, to offer special services, or to shift allocation of channelsused by a local paging service to accommodate traffic variations becauseof the fact that reception of channels in current systems is limited toa single channel fixed upon obtaining the paging receiver from thepaging service or to cyclically scan a group of closely spaced channelssuch as with the paging receiver used by the Metrocast system. The priorart paging receivers' inability to dynamically change the channels whichmay be received severely limits the usage of paging for business orother travel.

Currently, no paging system exists which effectively and at low costpermits paging on a regional, national and international level. This isa consequence of the inability of the paging receivers to dynamicallyreceive different and a large number of channels, the lack of a standardtransmission protocol which is compatible with existing analog anddigital transmitter hardware and existing systems not having a universalpaging receiver identification code which uniquely identifies each ofthe paging receivers throughout the world. The possibility exists in thecurrent systems of several pagers having the same paging receiveridentification code. Furthermore, the architecture of existing systemsis committed to the construction of dedicated communication linksbetween switches and/or the construction of new broadcast facilitiessuch as at the local switches which involves substantial capitalexpenditures. A universal paging receiver identification code is neededhaving the capacity to uniquely identify all of the paging receiversthroughout the world. Furthermore, in order to inexpensively implementregional, national and international paging, a system is needed whichutilizes existing local paging services without expenditures oncommunication links between switches or new broadcast facilities.

Currently in the United States, a relatively small number of channelsare used in the large metropolitan areas where most of the pagingtraffic occurs. As paging traffic increases in view of the relativelysmall number of channels predominantly in use in metropolitan areas,there is the likelihood that message traffic during the three peakpaging periods that occur each day will increase to the point where thepredominantly used small number of channels will become so busy that itis impossible to rapidly transmit pages to a paging receiver. Thiscondition has occurred in large metropolitan areas and results in delaysin pages being transmitted during peak traffic periods. Because of thefact that current paging receivers are not dynamically programmable toreceive pages on different channels existing networks do not have theability to dynamically switch channels on large metropolitan areas froma channel having the highest traffic to a channel or channels havinglower traffic, to accommodate paging traffic variations when one channelbecomes so busy that rapid paging is not possible. In fact, in largemetropolitan areas, there currently are VHF and UHF mobile channels thatare under-utilized due to the current cellular radio system which couldbe used as alternative paging channels to receive traffic on commonlyused stations.

Distinct FM analog and FM digital paging encoding protocols exist, butno universal encoding protocol exists which may be transmitted byexisting analog and digital FM paging transmitters and universallyreceived by paging receivers. Existing protocols for the FM analog anddigital paging systems do not have a high efficiency in transmittingdata per transmitted code. Existing digital transmitters modulate adigital FM transmitter with a binary signal which utilizes frequencyshift keying of the basic carrier signal to transmit the high level of abit with a burst of the shifted frequency and the low level of a bitwith the unshifted frequency of the carrier. Thus, each identifiabledigit of the transmission from an FM digital paging transmitter canencode only two distinct levels for each frequency burst of the carrier.Analog FM paging transmitters frequency modulate a sinusoidal carrierwith a total of 15 tones to create a hexadecimal value transmittingsystem in which no modulation of the basic carrier frequency isconsidered to be the "F" value and the remaining 15 different values areencoded by modulating the FM carrier with distinct tones. Pagingreceivers which are designed to receive analog transmissions requiresubstantial reception time of each tone to validly detect eachcharacter. Thus, while the protocol of FM analog paging transmitterstransmits a much higher number of data values for each frequency burst,the slowness of the paging receivers in detecting the discrete tonesdoes not result in a high throughput speed of transmitting characters.

Prior art alphanumeric paging (the capability of transmitting pageshaving numerical and alphabetic type characters) has been commercializedusing the above-referenced digital encoding protocol. Since only about15% of existing paging services use a digital transmitter, which isnecessary currently for implementing alphanumeric paging, the greatmajority of subscribers to paging services may not obtain alphanumericpaging. The analog protocol, which is based upon a hexadecimal toneencoding format, has not been utilized for encoding a character set totransmit alphanumeric messages.

Moreover, current alphanumeric paging service has been expensive toimplement both from the perspective of the paging service and from thesubscriber. The necessary input devices have proved to be expensive andthere is no standard input device design or data encoding protocol.Conversion equipment for changing an analog paging service to a digitalservice with alphanumeric capability has proven expensive and there isno existing computer system for changing an analog system to a digitalsystem which is inexpensive.

Existing paging systems which permit paging in multiple locations havethe deficiency when a subscriber desires to place a page from a locationremote from the subscriber file or to modify the level of service from alocation remote from the subscriber file of requiring a long-distancephone call to be made to the location where the subscriber file exists.Because of the fact that the long-distance phone call is charged to theperson wishing to make the page or change of service level or to theoperator of the system (800 service), the expense of using these pagingsystems is increased and may discourage users from making pages orchanges in the level of service by calling in from a location remotefrom the subscriber file. No national or regional prior art pagingsystem permits a page or a change in service level to be initiated froma geographic area outside the area where the subscriber file is locatedby making a local phone call to a switch in an area remote from theswitch containing the subscriber file within the system and further forthe paging receiver to be programmed to receive the page on a particularchannel used at the location where the page is to be received.

Current paging systems do not broadcast and current paging servicereceivers do not execute a repertoire of commands permitting thefunctional characteristics of the paging receiver to be programmeddynamically by RF transmission to the paging receiver. Current pagingreceivers do respond to commands which provide an alarm to the personwearing the paging receiver that a page has been received such asactivating a display and/or providing an audio alarm. However, currentpaging systems do not broadcast and current paging receivers do notexecute a diversity of commands in which the system influences operationand structure of the paging receiver, including commands activating thedisplay to indicate if the page has originated locally or from anotherregion, causing the message transmitted with the page to be stored in aparticular memory location in the paging receiver, programming thechannels on which the paging receiver is to receive pages, andpermitting the paging receiver to serve as a relay for pages either tobe transmitted or received and to interface with peripheral devices.

Cellular radio systems dynamically assign channels on which cellularradio receivers are to receive telephone calls. To make or receive atelephone call, a mobile cellular radio is locked onto a set up channelthrough communications with the transmitter which are established whenthe cellular radio receiver is turned on. The cellular system thenassigns the mobile cellular radio to a specific channel while the mobilecellular radio is making or receiving a telephone call within a cell. Asthe cellular radio receiver moves from one cell to another cell, thechannel is dynamically changed from one channel to another channel tomaintain a strong signal frequency. A cellular radio receiver does nothave a channel memory which stores channels which are to be scanned toestablish if a call is forth coming. The dynamic assignment of a channelis initiated by the transmitter for the sole purpose of establishing thechannel over which voice communications are to be initiated or to bemaintained when moving from one cell to another. Cellular radio systemsdo not assign channels based upon information assigned in a subscriberfile.

The telephone system is based upon a network of distributed switcheshaving a local/regional/national/international functionalresponsibility. In the United States local telephone offices areconnected to "lata" switches which are analogous to area codes but whichare identified by a different number pattern based upon systemconsiderations. The local, lata, and hub switches of the presentinvention operate in a fundamentally different manner than the switchesof the telephone system in that they perform substantial data processingto provide packets of data which are periodically transmitted to otherswitches to provide efficient and low cost operation. The operation ofthe telephone system is fundamentally different from a paging system inthat processing of calls in the telephone system is on a real-time basiswhich does not process calls to provide packets which are periodicallytransmitted and in that the initiation of a successful call requires thecaller to know the destination of the call (phone number), neither ofwhich occurs in a paging system.

A network known as ISDN (Integrated Service/Digital Network) has beenproposed. This network will interface with the telephone system andprovide data communications between switches in the network. Data is tobe transmitted in blocks between switches in the network. The proposaldoes not include disassembly, processing and reassembly of blocks ofdata by intermediate switches located along the communication pathbetween an originating and destination switch.

The X.25 transmission protocol has been developed which is used forsending a single block of data between an originating location and areceiving location. The prior art X.25 transmission protocol isidentical to that discussed with reference to FIG. 29 except that it hasnot been used in paging and further has not been used for transmittingmultiple blocks of data analogous to the multiple pages illustratedtherein.

U.S. Pat. No. 4,422,071 discloses a system for programming anidentification code of a receiver by a radio frequency communicationbetween a transmitter and the receiver.

SUMMARY OF THE INVENTION

The present invention provides a paging system having substantialadvantages over current paging systems. The paging system of the presentinvention is based upon utilization of existing transmitters which arein place at existing local paging services which eliminates the need forthe building of new transmitting facilities. Furthermore, the presentinvention utilizes existing communication facilities to transmitinformation between different switches in the system such as, but notlimited to, telephone lines. The use of existing communicationfacilities lessens the overall expense in constructing the network byeliminating the capital cost for new communication lines between theswitches such as with the Metrocast system. The system of the presentinvention is upwardly expandable by adding additional sublocal, local,lata and hub switches as the network expands, which currently may beaccomplished in a more cost-efficient manner than updating the capacityof a central switch.

The distributed switching network efficiently transmits pages locallyand between switches for performing regional and national paging withoutrequiring routing through a single central switch which processes pagesthroughout the system. The distributed network of switches permits eachof the individual switches to be implemented by a low-cost switchingnetwork controlled by a conventional PC with a processing assist fromdistributed processing units for processing input, output communicationsand data. The processing assist for data processing strips thecommunications protocol used for transmitting packets of pages to aswitch, converts the data code used for transmission of pages to thedata code used by the PC to process the pages, and converts the codeused by the PC back to the code used for transmission of pages betweenswitches and adds the communications protocol. The present inventionutilizes non-real-time communications with buffering of packets of pagesto be sent between switches and further buffers and batches pages to betransmitted between a local switch and an associated local transmitterwhich provides communications of pages between the switches and thelocal paging service and the local transmitter in a cost-efficientmanner.

The system functions to permit the channel or channels received by eachpaging receiver to be dynamically programmed which has the advantages of(1) increasing transmission spectrum efficiency by permitting thechannels carrying pages in a local paging service during high traffictime periods to be dynamically varied to maximize the efficiency of thetransmission of pages on existing paging facilities such as those foundin large metropolitan areas, (2) permitting pages to be made in aplurality of regions by dynamically programming the channels which areto be received by a paging receiver to be the same as those channelsavailable in the area in which the paging receiver is to receive thepage, (3) permitting battery savings to be achieved for paging receiverswhich are transported into an area outside of the local paging area bypermitting the paging receiver to respond to only pages which have adestination preamble which is transmitted as the first digit of thepaging receiver identification code to minimize the time during whichthe paging receiver is "on" to determine if the page is addressed to it,and (4) creating special service channels for use by local pagingservices.

The encoding format utilized by the invention is compatible with theexisting analog FM modulation and digital FM modulation transmittersused by local paging services which permits the utilization of existingbroadcast facilities in the network.

The distributed switching network minimizes the effects of switchmalfunction on the operation of the system and permits information to betransmitted through alternative switching paths, other than a normalswitching path, if a malfunction occurs.

The system permits pages to be made anywhere within a country orthroughout the world without long-distance charges being incurred byutilizing a geographically descriptive identification code which isprocessed by a lata switch receiving the request by local phone call fora page. The lata switch generates a page including the geographicallydescriptive identification number accompanying the request for a callwhich is forwarded by the network to the local switch having thesubscriber file storing the subscriber identification code serviceoption and the destinations to which pages are to be transmitted. Thelocal switch receiving the page generates a page in accordance with thelevel of paging service stored in the subscriber file and adds adestination(s) to the page in accordance with the stored destinationinformation accompanying the subscriber identification number.Furthermore, the information in individual subscriber files at eachlocal switch may be programmed by a local call made to a lata switchanywhere in the network without incurring long distance charges in amanner analogous to the placing of calls to request a page to a lataswitch as described above.

The paging system utilizes a command structure for sending pages whichdifferentiates between local and national pages which permits batterysavings by the paging receivers.

Each local paging service transmits pages with the digits of the pagingreceiver identification code transmitted in an order of increasingsignificance which minimizes battery consumption by the local pagingreceivers tuned to the frequency on which the pages are transmitted bypermitting a rapid determination of whether or not the page is addressedfor a particular paging receiver

Each local paging service transmits pages in a batched form which arebatched by the least significant digit of the paging receiveridentification code which further saves battery life of the receiver bypermitting an increase in the time interval between which the pagingreceiver is cyclically turned on to sample whether channel frequency ispresent.

The present invention provides alphanumeric paging which is fullycompatible with existing analog and digital transmitters. A universalencoding protocol is used which encodes each alphanumeric character astwo successive tones.

The system further permits the paging receiver to pass pages toperipheral devices which may function as data processors, printers,telex services, facsimile service or support for other types of dataprocessing devices.

The invention permits the integration of private paging systems andservices into a local paging service or into a common carrier network.Integration of the subscribers of private paging systems (non-radiocommon carrier) and services into the subscriber base of a local pagingservice functioning alone or contained in a network extends the serviceoptions which may be provided to subscribers of the private pagingsystems and services to those available in the local paging service ornetwork and extends the reception range of the paging receiver to thatof the local paging service or the network. The pages received from theprivate paging systems and services are broadcast by the transmitter ofthe local paging service to which they are directly connected and/or byother local paging systems that are part of the network.

The operation of paging receivers located anywhere in the network isdynamically controlled by one or more system commands which are added toeach page by the local switch at the time of origination of the page.The system commands are added by the local switch under the control of aprocessor, which upon matching an identification code accompanying thepage with a subscriber identification code stored in a subscriber file,adds one or more system commands to each page in accordance withselected service options stored within the subscriber identificationcode. For each selected service option one or more corresponding systemcommands are added to the page prior to transmission to a local pagingservice or to the network.

DEFINITIONS

The following definitions shall apply throughout the disclosure:

1. Jurisdiction--Jurisdiction is control exercised by a switch over oneor more additional switches to which the switch is connected or overpaging receivers having an identification code stored in a subscriberfile of the switch. A page is also a group of tones which is to betransmitted to a paging receiver and may include additional information,including identification code, one or more destinations, and a commandspecifying a function to be performed by a paging receiver.

2. Page--A page is a group of numerical or alphanumerical characters tobe sent to a paging receiver. A page may include additional informationincluding an identification code, one or more area destinations, and acommand specifying a function to be performed by a paging receiver.

3. Packet--A packet is one or more pages which are transmitted as agroup which have a switch as an area destination. A packet may have atransmission protocol and is transmitted between an originating switchand a destination switch.

4. Batch--A batch is a group of one or more pages which are forwarded toa transmitter for broadcast having one or more common paging receiveridentification code digits.

5. Sublocal Switch--A sublocal switch is the lowest level entry pointswitch in the network of the present invention.

6. Local Switch--A local switch is a switch having jurisdiction over anysublocal switches to which the local switch is connected and in theabsence of any sublocal switch being connected thereto is the lowestentry point into the network and has jurisdiction over subscribersstored in a subscriber file therein. The local switch may be associatedwith a common carrier local paging service.

7. Lata Switch--A lata switch is a switch having jurisdiction over anylocal switches to which the lata switch is connected.

8. Hub Switch-- A hub switch is a switch having jurisdiction over anylata switches to which the hub switch is connected.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system diagram of the present invention.

FIG. 2 is a block diagram of a local switch in accordance with theinvention.

FIG. 3 is a memory map of the random access memory of a local switch.

FIG. 4 is a block diagram of a lata switch in accordance with thepresent invention.

FIG. 5 is a memory map of the random access memory of a lata switch.

FIG. 6 is a block diagram of a hub switch in accordance with the presentinvention.

FIG. 7 is a memory map of the random access memory of a hub switch.

FIG. 8 is a flowchart of the operation of a local switch of the presentinvention.

FIG. 9 is a flowchart of the operation of a lata switch of the presentinvention.

FIG. 10 is a flowchart of the operation of a hub switch of the presentinvention.

FIG. 11 is a flowchart of the operation of the network in processingpages.

FIG. 12 is a flowchart of the operation of the network in processingpages called to a lata switch in the network.

FIG. 13 is a flowchart of the operation of the network in processing arequest for programming a subscriber file by calling a lata switchwithin the network.

FIGS. 14A and B are a circuit schematic of a PC DID Trunk Interface ofthe data input 30 in accordance with the present invention.

FIGS. 15A and B are a circuit schematic of a PC DID CPU Interface of thedata input 30 in accordance with the present invention.

FIGS. 16A and B are a circuit schematic of PC DID Audio Routing of thedata input 30 in accordance with the present invention.

FIGS. 17A and B are a circuit schematic of a PC DOD Trunk Interface ofthe data output 34 of the present invention.

FIGS. 18A and B are a circuit schematic of a PC DOD CPU Interface of thedata output 34 of the present invention.

FIGS. 19A and B are a circuit schematic of PC DOD Audio Routing of thedata output 34 of the present invention.

FIGS. 20A and B are a circuit schematic of a PC MF Trunk Interface ofthe MF and DTMF Processor 44 of the present invention.

FIGS. 21A and B are a circuit schematic of a PC MF CPU Interface of theMF and DTMF Processor 44 of the present invention.

FIGS. 22A and B are a circuit schematic of PC MF Audio Routing of the MFand DTMF Processor 44 of the present invention.

FIGS. 23A and B are a circuit schematic of the PC XT Data Channel Boardof the data module processor 32 of the present invention.

FIGS. 24A and B are a circuit schematic of the PC XT Channel Registerand Modems of the data module processor 32 of the present invention.

FIGS. 25A and B are a Data Board Memory Map of the data module processor32 of the present invention.

FIG. 26 illustrates a block diagram of a system used by a paging service18 in dynamically switching paging receiver reception channels betweenone channel and one or more additional channels.

FIG. 27 is a flowchart of the operation of the system of FIG. 26.

FIG. 28 is a diagram of a local switch 12 and a plurality of sublocalswitches.

FIG. 29 is a diagram illustrating the digits of the subscriber andpaging receiver identification code and their order of transmission fora page broadcast for a local service option.

FIG. 30 is a diagram illustrating the digits of the subscriber andpaging receiver identification code and destination code and their orderof transmission for a page broadcast for service options other than alocal service option.

FIG. 31 illustrates a preferred embodiment of the protocols of a packetand a page in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS I. System Overview

FIG. 1 illustrates a diagram of a paging network 10 in accordance withthe present invention which provides worldwide paging capability. Thesystem is a distributed network of switches comprised of a plurality oflocal switches 12, a plurality of lata switches 14 and a plurality ofhub switches 16 with each switch being located in a differentgeographical location within an area being serviced by the system. Thehub switches 16 may be located totally within a country to providenational service or in multiple countries to provide internationalservice. In order to simplify the drawings only a single portion of thenetwork is labelled with reference numerals with it being understoodthat repeating portions exist such as for that portion under thejurisdiction hub switch #P. Communication links which are illustrated asa dotted arrow represent network structure which has been omitted forclarity that is identical to structure that is illustrated in detail.Additionally, one or more sublocal switches as discussed with referenceto FIG. 28 below may optionally be provided within the system under thejurisdiction of the local switch. The sublocal switches have beenomitted for purposes of clarity. Each switch has jurisdiction over ageographic area. The functions performed by the local switch 12, thelata switch 14 and the hub switch 16 are described below. Thearchitecture of the local, lata and hub switches are similar to eachother with a preferred embodiment of the hardware being illustratedbelow in FIGS. 14-25. A block diagram of the local, lata and hubswitches is discussed below with reference to FIGS. 2, 4 and 6. Thecontrol programs used with the sublocal, local, lata and hub switchesare set forth in the above-referenced Microfiche Appendix. A singleoverall control program is used in each of the sublocal, local, lata andhub switches with the program of each switch being programmable by atechnician setting up the switch by inputs from a keyboard to programthe specified function to be performed by the switch. A local pagingservice 18 is typically connected to each of the local switches 12 whichoffers other paging services than that provided by the present inventionalthough it should be understood that the local switch may be usedexclusively to control all services offered at the local level. Thelocal paging service 18 is typically an existing common carrier pagingservice which services an area within broadcast distance of atransmitter 15 under the jurisdiction of the local paging service towhich the local switch 12 has been connected to permit the local pagingservice to function in the network. The transmitter 15 may be either ananalog or digital transmitter as discussed above with reference to theprior art. Communications between the local, lata and hub switches maybe by any existing communication medium 20 such as direct dial-upcircuits (IDD Circuits International), direct outward dial circuits(end-to-end), in-bound watts (and other in-bound services that arevolume discounted), out-bound watts (and other out-bound services thatare volume discounted), feature group A (U.S. service), feature group B(U.S. and European services), MF tie trunks (U.S. and Europeanservices), and direct inward dial (international service, whereavailable), as well as any future medium which permits pages to betransmitted between switches. Each of these services are indicatedschematically by a bi-directional arrow 20 which interconnects a localswitch 12 to a lata switch 14, a lata switch 14 to a hub switch 16, anda hub switch 16 to another hub switch 16. Furthermore, the localswitches 12 are connected to a local paging service 18 by acommunication link 22 of any conventional nature, including wiresconnecting the local switch to the local paging service. Each switch isprovided with a local telephone trunk 27 which functions as amaintenance port. Furthermore, dotted bi-directional lines 24 illustratealternative communication paths between switches which may be used inthe case of malfunction or busy conditions. It should be furtherunderstood that the invention is not limited to any particularcommunication protocol linking switches, nor connecting the local switchto the local paging service. A telephone trunk 28 functions as an inputfor manual (telephone handset) and automatic device entry of pages asdescribed below.

The network 10 provides numeric, alphanumeric and data services to allpoints within the United States and participating countries. In thepreferred embodiment of the network, a universal code is used forencoding transmissions of characters over both the communication links20 and 22 which is compatible with existing analog and digitaltransmitter 15. The universal code discussed below utilizes sixteentones for encoding all characters for transmission between switches orto a local paging service 18. For numeric paging each character istransmitted as successive single tones and for alphanumeric paging eachcharacter is transmitted as two successive tones as discussed below indetail. An X.25 transmission protocol as discussed below in detail ispreferably utilized for transmitting packets of pages between switches.While in the preferred embodiment, a preferred code and transmissionprotocol is utilized it should be understood that the invention is notlimited thereto.

The network 10 is economical to implement and operate as a consequenceof utilizing distributed processing technologies, and transmission ofpages periodically in packets of pages between the switches. Dynamicinteraction between a frequency agile pager, which preferably is of thetype described in the above-referenced patent applications filed on Oct.20, 1987, and the network 10 efficiently utilizes transmission time thatis available in the channel spectrum. One of the distinct advantages ofthe network 10 is that it utilizes existing paging common carriers todeliver pages to the end user with existing paging RF coverage in theUnited States being greater than 85% of its geographical area with justtwo 150 MHz frequencies, with a total of 10,500 additional channelsbeing available for paging receiver use. Wire line common carriers,private systems, hospital, government, emergency and many other servicescan be accommodated by the utilization of dynamic channel. programming,as described below, by the network 10 to change the channel on whichindividual paging receivers may receive pages. The network 10 incombination with its paging receiver described in the above-referencedpatent applications filed on Oct. 20, 1987 presents a universal productuseful throughout the world.

The network 10 provides an integrated sublocal, local, regional andnationwide paging network that is transparent to use by the subscriberand provides for pages to be called into an existing local pagingservice 18 by the making of a local phone call on a telephone trunk 28connected to the local switch 12 in a conventional fashion as well as toany lata switch 14 throughout the network 10 by a local phone call totelephone trunk 26, as is described below. The functionality ofpermitting pages to be originated anywhere within the network 10 bylocal telephone call, preferably by calling a single number within thecountry (950-XXXX) avoids the telephone expense and system overheadcaused by calling of a central switch to originate a page such as in theMetrocast system which necessitates providing a high capacity expensiveswitching system. It should be understood that the network's usage ofperiodically transmitting packets of pages between switches results in amuch lower cost than the cost of 800 or conventional long distanceservice. The phone trunk 26 for calling the lata switch 14 to place apage anywhere within the network 10 is indicated by bi-directionalarrows to each lata switch 14. As will be described below, regardless ofthe location of the person making the telephone call to a lata switch 14over telephone trunk 26 to originate a page, the lata switch 14 willformulate a page with the destination specified by geographicallydescriptive digits of the identification code inputted with the call torequest a page to the lata switch and the network 10 will automaticallyroute the page through the switches of the network to the person beingpaged by way of the local switch 12, which stores the subscriber file 54described below with reference to FIG. 3, that stores the identificationcode of the subscriber and paging receiver The local switch 12 whichstores the identification code inputted with the page in its subscriberfile adds one or more destinations to the page and transmits the page(s)to the local paging service 18 and/or the network 10 by way of the lataswitch 14 having jurisdiction. The person placing the page by callingthe local switch 12 on telephone trunk 28 or the lata switch 14 ontelephone trunk 26 does not have to know the location of the personreceiving the page.

II. Local Switch

The local switch 12 is connected to a participating common carrierpaging service 18 located in a particular geographic area. The localswitch 12 has local direct inward dial trunks 28 which permits thesubscriber to use a local telephone call to place a page. Pages over thelocal telephone trunks 28 may be (1) numeric characters which areentered manually by DTMF tones or other telephone coding mechanisms, (2)alphanumeric characters which are entered manually by DTMF tones orother coding mechanisms, (3) alphanumeric characters which are enteredby an automatic message inputting device using an encoding format havinga transmission protocol of conventional nature such as DTMF tones or (4)a high speed (baud rate) encoding protocol such as the X.25 protocoldescribed below. With reference to FIG. 2, the top input to data input30, which is labelled "Manual and LOW SPEED Automatic Pages", receivesthe first three inputs and the bottom input to the data input, which islabelled "HIGH SPEED AUTOMATIC" receives the fourth input. It should beunderstood that any number of inputs to the data input 30 may be used inpractice. The local switch 12 has voice prompting which facilitates theperson placing a call on the telephone trunk 28 to enter a message to betransmitted as a page.

Pages which are entered by the telephone trunk 28 in the four differentformats described above are encoded with a command structure as follows.Manually entered numeric character pages consist of digits encoded bythe telephone handset. An entry of this type does not have a commandheader. Manually entered alphanumeric character pages may be entered bythe following format consisting of two successive DTMF tones or rotarydial inputs:

    ______________________________________                                        Numeric:   All numbers are sent as themselves preceded                                   by a zero.                                                         Alphanumeric:                                                                            A = 21    H = 42   O = 63 V = 83                                              B = 22    I = 43   P = 71 W = 91                                              C = 23    J = 51   Q = 11 X = 92                                              D = 31    K = 52   R = 72 Y = 93                                              E = 32    L = 53   S = 73 Z = 12                                              F = 33    M = 61   T = 81 Space = 00                                          G = 41    N = 62   U = 82                                          ______________________________________                                    

An asterisk is used as a command header which precedes the alphanumerictransmission of a manually entered alphanumeric character page.Automatic input from an input device, which is audio coupled to thetelephone handset, is encoded with a double (repeated once) asteriskcommand and preferably utilizes the hybrid coding format discussedbelow. Input from a high speed automatic entry device, having an X.25transmission protocol, is encoded with a triple (repeated twice)asterisk header and is preferably encoded in the hybrid coding formatdiscussed below at a high baud rate such as 1200 baud which necessitatesa much shorter tone duration than that used by the transmitters 15. Thecommand header is decoded by the data input 30 discussed below withreference to FIG. 2 to control the processing of the different datainput formats from the telephone trunk line 28.

Furthermore, following the command header in all inputs, except for themanually entered numeric character input, is a language field which isused to encode whether the page is for transmission in English orJapanese. The dual language capability of the system is discussed below.The processing by the system of pages in two languages is totallycontrolled by the aforementioned language field. As will be discussedbelow, the language field controls the commands which are placed witheach page except for purely number pages. The individual pagingreceivers decode the command and display the page in the languagedictated by the command.

The local switch 12 processes the pages received from the telephonetrunk 28 and from the associated lata switch 14 to which the localswitch 12 is connected by the communication link 20 as described belowin detail. It should be understood that the local switch 12 hasprogramming which automatically and dynamically monitors paging trafficwhen a plurality of transmission channels are used and allocates thechannels available to the paging service 18 for transmission to thepaging receivers to maximize the local paging services paging throughputas described below. The local switch 12 calls the resident local pagingterminal of the paging service 18 and determines how much air time ithas to deliver a batch of pages to the transmitter 15 associated withthe local paging service. The local switch 12 then calls the localpaging terminal of the local paging service 18 and transmits a batch ofpages encoded in the hybrid encoding format described below which iscompatible with existing analog and digital FM paging transmitters.

The local switch periodically transmits packets of pages stored in itsoutbound lata buffer 82 over communication link 20 as described below inconjunction with FIG. 3 to the lata switch 14 having jurisdiction overit which provides cost efficient transmission and efficient pageprocessing by avoiding processing by a single central switch controllingthe network as in the prior art. This architecture is highly efficientin routing the pages originating at the local switch 12 to betransmitted by the network 10 which are intended for broadcast by atransmitter remote from the local switch having the subscriber filestoring the identification code of the subscriber to be paged.

In the preferred embodiment, when the paging subscriber desires toreceive regional, national, or international service, the local lataswitch 12 is programmed by the subscriber by simple telephone area codeentries which identify the service areas although it should beunderstood that the invention is not limited to the usage of telephonearea codes to identify the service areas. The programming isaccomplished by adding or deleting one or more area codes of thesubscriber's destination field 78 contained in a subscriber file 54maintained in the subscriber's local switch 12 described below withreference to FIG. 3. In the United States, area codes are used for easeof subscriber use and telephone books may then serve as the service areadirectory. The same ease of use is available to worldwide customers withcounty-city code entries available from telephone books in any airport,hotel or business.

The local switch controls the generation of individual pages having themessage detail as described below with reference to FIG. 31. The numberof pages which are generated in response to a page received without anarea destination from the telephone trunk 28 or from a lata switch 14 isdetermined by the central processor of the local switch 12 interrogatingany area destinations listed in the destination area code field 78 asdescribed below with reference to FIG. 3. Each page generated by theprocessor contains the same message content. A separate page isgenerated for each destination area listed in field 78 and if the localservice option of the service option field 68 is selected, an additionalpage is generated for broadcast by the local paging service 18 withoutan area destination in the network which is processed by the localswitch 12 as a page received from the network for broadcast by the localpaging service 18. Furthermore, each individual page generated by alocal switch contains one or more commands which are discussed. Thecommands which are added to each page transmitting a message aredetermined by the operation of the central processor of the local switch12 in response to interrogation of the selected service options of field68. Programming of paging receivers with the channel programming commandis in response to the local switch programming the paging receiver toreceive one or more channels subscriber programming of destination areasin field 78, and the degree of utilization of the channels of the localtransmitter 15 as described below with reference to FIG. 26.

The central processor of the local switch 12 processes each individualpage received from the network to determine if it originated from alocal switch 12 or a lata switch 14. This determination is made bydetermining if a destination header identifying a lata switch 14originating the page precedes the paging receiver identification code ina packet having the configuration of FIG. 31. In the absence of theheader (which is a geographic identification of the originating lataswitch 12 in the network) in an individual page, the page is processedexclusively by the local switch 12 for broadcast by the associated localpaging service 18 without interrogation of a subscriber file in thelocal switch. If the header is found in a page, the central processorprocesses the page as either a request to reprogram the subscriber fileor as a page received on the telephone port 28 without an areadestination which must be processed to determine one or more areadestinations and formed into new pages each with a different areadestination from the field 78 if transmission by the paging network isto occur and into a page without an area destination if transmission bythe local paging service is to occur as described below.

The local switch 12 also serves as the dynamic programming interfacebetween the paging receiver and the network 10. The local paging service18 may program channels to be received by paging receivers, changesubscriber identification codes and add new customers to the network 10utilizing the local switch 12. The functionality of the paging receivercan be changed from a fixed channel to a multi-channel or a scanningpager as required by use of the channel programming command discussedbelow.

Messages originating at the local switch 12 which are transmitted to thelata collector switch 14 having jurisdiction over it are packetized asdescribed below with reference to FIGS. 2 and 3. Destination area codes(telephone area codes or other geographically descriptive code) areadded to pages prior to transmission to the lata switch 14 as describedbelow and the paging receiver is dynamically and automaticallyreprogrammed for the new service areas by the local switch 12 issuingchannel programming command(s) in the form of a page as described belowwhich ensures that the paging receiver is programmed to receive channelsin each designated area. The current paging channels remain in the pagerto avoid loss of a message while a subscriber is still in the area.

III. Lata Switch

The lata switch 14 provides a second tier of network intelligence. Thisintelligence includes page processing, packetizing and routing. The lataswitch 14 receives packets of pages from each of the local switches 12within its jurisdiction as well as the hub switch 16 having jurisdictionover it. The lata switch 14 provides the geographical presence for thenetwork 10 to originate and terminate paging messages utilizing dial-upor dedicated communication services.

The lata switch 14 is responsible for collection of pages from the localswitches 12 within its jurisdiction. When a packet of pages is receivedfrom the local switch 12, it is disassembled, processed and stored fortransmission to the proper destination(s) in one or more packets eachconsisting of one or more pages which are intended for destination(s)either within or outside the lata switch jurisdiction. The lata switch14 periodically transmits packets of pages stored in its outbound hubbuffer 98 and its outbound local buffer 104 described below withreference to FIG. 5 to the associated hub switch 16 having jurisdictionover it and to local switches 12 within its jurisdiction which providescost efficient transmission and efficient page processing by avoidingprocessing by a single central switch controlling the network 10. Thisarchitecture is highly efficient in routing pages originating within thejurisdiction of the lata switch 14 which are intended for broadcastoutside its jurisdiction as well as distributing pages from one localswitch 12 to one or more additional local switches within thejurisdiction of the lata switch. If the page is destined fordistribution within the jurisdiction of the lata switch 14, the page isprocessed into packets of pages for transmission to each of the localswitches 12 within its jurisdiction or alternatively to less than all ofthe local switches in its jurisdiction. The pages are then periodicallytransmitted as packets to the local switches 12 within the jurisdictionof the lata switch 14.

The lata switch 14 is also responsible for collection of pages outsideits jurisdiction to be broadcast to the local switches 12 within itsjurisdiction. Packets of pages received from the hub switch 16 aredisassembled, processed, and packetized for transmission to thedestination local switches 12.

The lata switch 14 also serves as a source of regional paging billingcollection. The lata switch 14 will be interrogated periodically toobtain the call records for pages within its jurisdiction that have beendistributed to each of the local paging services 18 associated with thelocal switches 12 within its jurisdiction. A dial-up modem port 27 isutilized for this function.

The function of the lata switch 14 in collecting requests for placingpages in the network or to reprogram the subscriber file 54 of a localswitch 12 by placing a local phone call on telephone trunk 26 is animportant aspect of the present invention. The lata switch 14 places theheader discussed above, which geographically identifies the lata switch14 originating the page in front of the paging receiver identificationcode, in a packet as illustrated in the message detail of FIG. 31 toenable the local switch 12 to differentiate between pages which are forbroadcast by the local paging service 18 associated with a receivinglocal switch 12 and pages which require access to the subscriber files54 to generate one or more pages for broadcast or pages forreprogramming a subscriber file. Preferably, the header is four digitscomprised of a country code followed by the telephone area codeidentifying the lata switch 14 which received the call for theoriginating page. The commands utilized by the local switch 12 in thepacket configuration of the message detail of FIG. 31 discussed belowwith reference to system commands are not utilized by the lata switch.

IV. Hub Switch

The hub switch 16 provides the third tier of network intelligence andserves as an inter-regional communications link. One hub switch 16 willpreferably be located in each international region to serve as a networkrouting switch. In the United States, a hub switch 16 will be locatedwithin the region served by each of the Bell regional companies(RBOC's). Accordingly, in the United States the preferred implementationof the network 10 includes seven distinct hub switches 16. Each hubswitch 16 in a preferred embodiment can have fifty-five lata switches 14under its jurisdiction. The hub switch 16 also serves as a networkrouting switch for inter-hub calls when pages are to continue in thehub-to-hub network.

When a packet of pages is received from either another hub switch 16 ora lata switch 14 within its jurisdiction, the pages are disassembled forexamination. Each page is examined for its destination address(es). Adetermination is made if the hub switch 16 should forward the page toone of the six adjacent hub switches or forward the page to a lataswitch 14 within its jurisdiction as described below in detail. Thepages are then destination processed and packetized for transmission toeither another hub switch 16 or a lata switch 14 within itsjurisdiction. The first hub switch 16 to receive a page to betransmitted between hub switches will also provide nationwide billingrecords. The hub switch 16 will be interrogated by a dial-up modem 27 totransfer the message records to the billing center.

V. Switch Architecture

Each of the sublocal, local, lata and hub switches utilize the samehardware with changes in function being implemented by programming atthe time of installation. The control programs for each of theprocessors in the sublocal and local, lata and hub switches, which areset forth in the Microfiche Appendix referred to above, are modified bykeyboard input to perform the desired function of each of the differentswitches.

A. Local Switch 12

FIG. 2 illustrates a functional block diagram of the local switch 12.The local switch 12 is comprised of a data input terminal 30, a datamodule processor 32, a data output 34, a keyboard and monitor 36, aprinter 38, floppy and hard drive disks 40, a modem 42, MF and DTMFprocessor 44, a read-only memory (ROM) 46, a random access memory (RAM)48 and a central processing unit (CPU) 50. Each of the aforementionedelements are connected to a data bus 52.

The local switch 12 serves as the primary point of entry into thenetwork 10. Each participating common carrier (local paging service 18)is furnished a local switch 12 to perform diverse functions. The localswitch provides both DID (direct dial) and DOD (over-dial) access tolocal subscribers issued a paging receiver. Voice synthesized promptingallows customers to readily enter the necessary identification code toactivate a page and numeric messages. Entry for alphanumeric characterpages also takes place on the DOD and DID trunks via a slow-speed(manual or automatic) DTMF entry or high-speed modem (X.25 protocol).

The local switch 12 performs a number of important functions. The localswitch 12 permits local subscriber entry from the keyboard 36 or themodem 42 to change the subscriber file 54 as described below withreference to FIG. 3 upon inputting a correct secret code. The localswitch 12 provides for the batching of local pages to be sent to thelocal paging service 18. Pages to be transmitted throughout thejurisdiction of the lata switch 14 associated with a local switch 12 andnationwide pages to be transmitted to a plurality of lata switches 14are formed into packets and forwarded to the lata switch havingjurisdiction over the local switch 12 for distribution to the network10. Packets of pages to be transmitted by a local paging service 18which are received from the network 10 are received from the lata switch14 having jurisdiction over the local switch 12 by means ofcommunication link 20.

The CPU 50 performs the overall control of the local switch 12 withprocessing assists as described below from the data input 30, datamodule processor 32 and data output 34. The CPU 50 formats each requestfor a page which is inputted by the telephone trunk 28 to include thepaging receiver identification code in an order of increasingsignificance of the digits from the least significant digit to the mostsignificant digit, a destination(s) as determined by interrogation offield 78 as described below with reference to FIG. 3, a command asdetermined by interrogation of the service option field 68 as describedbelow with reference to FIG. 3 and the language field inputted with thepage. As explained below, the formatting and broadcast of the pagingreceiver identification code digits in an order of increasingsignificance produces substantial battery savings for each of the pagingreceivers in the system.

The CPU 50 may be any processing system but, in a preferred embodimentof the present invention, is a PC AT processor based upon an Intel 80286microprocessor. The control program for the CPU 50 is set forth in theabove-referenced Microfiche Appendix. The PC will be provided with aplurality of slots for receiving circuit boards carrying the data module32, modem 42, data output 34, data input 30 and blank slots forexpansion.

1. Data Input 30

The data input 30 performs the important function of being the input forall pages inputted by the telephone trunk 28 and the input of pagesreceived from the network 10 which are addressed to the lata switch 14having jurisdiction over the local switch 12. The data input 30 decodesthe command format of the inputted pages discussed above from the trunklines 28. Page inputs on the trunk lines 28 which are not in X.25protocol are converted into ASCII with the rate of conversion beingcontrolled by the decoded command. It further strips all inputs, whichare not in X.25 protocol, of any communication protocol, that istypically in a DTMF format, and converts the pages into ASCII code forstorage in the buffer 84 of the RAM 48 as discussed below with referenceto FIG. 3 and subsequent processing by the CPU 50. All inputs in theX.25 transmission protocol to the local switch, whether from a lataswitch 14 or from a telephone trunk line 28, are forwarded to the datamodule processor 32 for stripping of the X.25 transmission protocol, asdiscussed below with reference to FIG. 31, and for conversion into ASCIIcode format for storage in buffers 80 and 84 of the RAM 48 of FIG. 3discussed below.

A preferred embodiment of the data input 30 is illustrated in FIGS. 14(Aand B)-16(A and B). Integrated circuits are identified by their industryor manufacturer's designation. A control program for the data inputprocessor is set forth in the above-referenced Microfiche Appendix. Thecontrol program for the data input processor is programmable by inputfrom the keyboard 36 to alter its function to perform the inputting ofdata for any one of the sublocal, local, lata and hub switches. The datainput 30 contains support for four direct inward dial DID trunks. Digitsout-pulsed from the central telephone office may be rotary dial or DTMFtones up to sixteen digits in length. The data input 30 supportsimmediate or wink-start trunks. A preferred implementation of the DIDtrunk board with trunk interfaces is illustrated in FIGS. 14A and B.Validation relay U37 provides the necessary tip-ring line reversals forcall validation. The U38 electronic SLIC provides the two-wire tofour-wire conversion for the on-board electronics. Resistors R4 and R5determine the line impedance for the 2006 SLIC. Hybrid balance is set byresistor R6 at 40/60 db. Off-hook seizure of the trunk is detected bythe 2006 SLIC. The off-hook logic is routed to U26 for detection by theon-board processor. The off-hook output also detects rotary dialsignalling. The line amplifier U57 provides an adjustable input andoutput level for DTMF tones and voice messages. The U15 8870 DTMFdecoder detects dialed-up and "over-dialed" digits sent from the centraloffice or the subscriber. The data valid output of the U15 8870 DTMFdecoder is routed to U26 for detection by the microprocessor. The validdate relay is controlled by the relay driver U83 and the control latchU28.

FIGS. 15A and B are discussed as follows. FIG. 15A contains the residentmicroprocessor U39 of the data input 30 which has 32 bytes of storedprogram in EPROM (U1 and U2) and 24K bytes of RAM (U3, U40 and U41) fortemporary message storage contained in FIG. 15B. The residentmicroprocessor applies the buffer address of the inbound pages buffer 84to pages that are inputted by the telephone trunk 28 in non-X.25protocol. The operational status of the resident processor is monitoredby watchdog timer U30. In the event of processor failure, the watchdogtimer alerts the CPU 50 that a malfunction exists. The data interchangebetween the resident microprocessor of the data input 30 and the CPU 50takes place with the bi-directional latch U56. Buffer status latches U53determine the status of data entering and exiting the data input 30.Board address decoding is determined by the U76, U77, U78 and U21. Theaddress jumpers are set to determine the starting address field for thedata input.

FIGS. 16A and B contain the voice messaging synthesizers, the audiomatrix switch and the DTMF encoders of the data input 30. The voicesynthesizer is under direct control of the CPU 50 via the word latch U43and functions to provide necessary voice prompting between personscalling in pages or programming their subscriber file. The startingaddress of the word addresses the speech ROMs U9 and U10. The U6 HC 4040word address counter presents the four-bit ADPCM words to the U8 HC 4019four-bit gate to the U12 5205 voice synthesizer message. The voice audiois routed through the U49 22101 audio matrix switch to the respectiveDID trunk.

Dedicated trunk DTMF encoders U22, U23, U45 and U44 encode digits sentto the trunks 1-4, respectively of the data input 30. The encoded digitsare sent from the microprocessor to the respective encoder. The outputlevels are present relative to the adjusted audio level from the lineamplifiers for a level equal to the maximum voice level.

2. Data Output 34

The data output 34 performs several functions. For batches of pageswhich are destined for the local paging service 18, the data outputconverts the pages as outputted from the ID code buffers 86 from ASCIIto the hybrid encoding format discussed below. However, it should beunderstood that the invention is not limited to the use of the hybridencoding format. For packets of pages which are destined for the lataswitch 14, the data output 34 accepts the pages which have beenformatted in the X.25 transmission protocol by the data module processor32 as described below and outputs them to the lata switch overcommunications link 20. A preferred embodiment of the data output 34 isillustrated in FIGS. 17(A and B)-19(A and B). A control program for thedata output 34 is set forth in the above-referenced Microfiche Appendix.The control program is programmable by input from the keyboard 36 toalter its function to perform the outputting of data for any of thesublocal, local, lata and hub switches. Integrated circuits areidentified by their industry or manufacturer's designation. Thetransmission of pages from the data output 34 are periodic (non-realtime) to both the lata switch 14 having jurisdiction over the localswitch 12 and to the local paging service 18.

The ports of the data output 34 perform the following functions. A firstport serves as the network entry/exit point for the network. X.25 datapackets are sent and received between the first port which is connectedby communication link 20 to the lata switch 14 having jurisdiction. Thefirst port utilizes a two-wire subscriber line to send X.25 encodedpackets which originate from the local switch 12 to the lata switch 14having jurisdiction. Ring-in on the port connected to the lata switch 14initiates a network answer and network paging data can be down-loadedfrom the lata switch 14. The second port of the data output 34 mayperform any one of three functions. It may operate as a telephone portas described above. When operated as a telephone port, it dials into anunused DID trunk of the local paging service 18. An unused telephone andvoice pager is assigned to the terminal of local paging service 18. Thispermits functioning as the local paging service 18 front-end entry tothe network 10. This configuration is especially useful when the localpaging service 18 has an existing analog compatible transmitter. Thesecond function of the second port is a stand-alone paging switchconnected directly to a locally controlled transmitter 15 in the localpaging service 18 or "hand-shaked" with an existing analog system. Theoutput audio is paralleled or switched with the transmitter controlledlocal control connections. Hand-shake inputs and outputs permit thelocal switch 12 and the terminal of the local paging service 18 to"share" transmitter control without collisions. A collision is when oneterminal attempts to page while the other is paging on the transmittercontrol pair. In this configuration, the local collector may operate asa stand-alone or "shared" terminal. The third function of the secondport permits the local switch 12 to operate as a stand-alone or sharedswitch for a digital-only paging service 18. In the stand-alone digitalconfiguration, the local switch 12 is connected to the digitaltransmitter 15 via the data and transmitter keying control logicoutputs. When shared with an existing digital transmitter, the datatransmitter control and hand-shake control lines are routed through thelocal switch 12 for control.

The data output 34 contains a resident microprocessor to control thelocal and network ports, encode and decode telephone digits. Themicroprocessor performs the important function of converting ASCIIencoded batches of pages which are received from the ID code buffers 86for transmission to the local paging service 18 into the hybrid encodingformat discussed below which is compatible with analog or digital FMpaging transmitters. Each characterpage of a page which is transmittedwith the A4, C4, A6 and C6 commands is encoded with sequential tonesdiscussed below to be transmitted to a local paging service 18 is by twotones in accordance with the tale set forth below whether the page is tobe in English or Japanese. The pages previously grouped by the CPU 50 inthe ID code buffers 86 are buffered in the data output until theirperiodic transmission. The data output 34 controls the transmitter 15 ofthe local paging service 18. A prompting voice synthesizer and the audiomatrix switch for routing X.25 formatted packets of pages are alsocontained in the data output 34.

FIGS. 17A and B contain the telephone trunk interface electronics. Whenboth ports are used in a dial-up configuration, the U19 and U20 2041electronic RSLIC's convert to the two-wire TIP-RING to a four-wirecircuit. An internal hybrid provides the necessary isolation. Ring-indetection and seizure of the telephone circuit are also accomplished bythe RSLIC. The U70 and U72 1458 line amplifiers provide gain forreceiving and transmitting audio. DTMF digits are decoded by the U41 andU43 8870 decoders. Telephone office tones are detected by the U69 andU70 M980 detectors. Tones are monitored by frequency and cadencepermitting the sequence for determining call status. A U18 or U21 5088DTMF encoder is utilized under direct processor control to originateDTMF signalling digits.

FIGS. 18A and B contain the resident microprocessor (U22), RAM (U3-U5)and EPROM (U1 and U2) memories utilized for the stored program and thebuffering of messages. Storage of 32K bytes of stored program and 24K ofRAM memory are utilized for these functions. The address jumpers arelocated within the appropriate bus buffer U66 and status latch U33. Awatchdog timer U45 monitors the operation of the processor and alertsthe switch when a malfunction is detected.

FIGS. 19A and B contain the voice message synthesizer, X.25 matrixswitch and the paging protocol encoder for encoding batches of pagesreceived from the ID code buffers 86 for transmission to the localpaging service. The protocol encoder U28 is under direct control of theprocessor via the latch U24. The analog protocol is converted into adigital waveform by U46 and U57 when digital outputs are used from theboard. The U25 22101 audio matrix switch routes pages to and from theCPU 50 and also routes the voice messaging audio to the network ports.The voice synthesizer U54 synthesizes words stored in ROM memories U6and U29 that are selected by word latch U26. Message generation is underdirect control of the processor of the microprocessor.

3. MF and DTMF Processor 44

The MF and DTMF processor is utilized when interfacing to four-wire Eand M trunks requiring MF signalling and bi-directional supervision. TheMF and DTMF processor 44 contains two trunks, the MF encoders anddecoders and DTMF encoders and decoders under the direct supervision ofan on-board microprocessor. A preferred embodiment of the MF and DTMFprocessor 14 is illustrated in FIGS. 20(A and B)-22(A and B). Integratedcircuits are identified by their industry or manufacturer's designation.The program of the resident microprocessor is set forth in theMicrofiche Appendix.

FIGS. 20A and B are described as follows. FIG. 20A contains the trunkline amplifiers U58 and U59 for the two trunk pairs. The "E" leadsupervision inputs for each trunk are controlled by the opto-isolatorU56. Current is limited to 15 milliamps in each of the "E" lead circuitsby resistors R25 and R26 for trunks 1 and 2, respectively. The "M" leadcontrol for each trunk is provided by relays U15 and U35 withcurrent-limiting resistors R27 and R28. The "M" lead is at abattery-common potential when at rest and changes to a -48 volt batteryduring wink and supervision periods. The "E" lead logic signals arerouted to the processor for interpretation. FIG. 20B performs thefollowing functions. The "M" lead control is under direct control of themicroprocessor via latch U11. DTMF encoders and decoders are provided.The U34 and U55 8870 decoders contain the amplifiers, filters and tonedetection electronics to detect the presence of DTMF tones. When a toneis detected, the microprocessor is alerted via the DV (data valid)output on pin 15. DTMF tone generation is accomplished by the 5088encoders U13 and U33. Tone duration is microprocessor controlled withthe tone enable latches U27 and U32. Modem audio and voice messaging isrouted to the audio matrix switch for distribution.

FIGS. 21A and B contain the microprocessor and related supportelectronics. The U46 master clock for the processor U16 is a 3.58 MHzand is utilized for the DTMF encoders and decoders and the interrupttimers. The master clock frequency is divided by two by U44 and sent tothe clock input of the processor. Five millisecond interrupts aregenerated by the 3.5 MHz divider U45 and the EXCLUSIVE OR gate U43.Every 5 milliseconds, the processor determines if any change ininput/output functions has taken place. The processor also uses the 5millisecond interrupts as a timer reference for determining timing andsignalling sequences. Two 27128 16K byte EPROM memories (U1 and U2)contain the stored program for the microprocessor. Memory of 24K bytesof RAM (U3-U5) are used for temporary storage of pages to be sent orreceived via DTMF signalling and trunk status. A watchdog timer U39monitors the status of the data bus and, upon failure of themicroprocessor, alerts the central processing unit 50. The input/outputinterface between the MF and DTMF processor 44 and the CPU 50 utilizes abi-directional tri-state latch. The latch U54 can send, receive andstore messages simultaneously. The address of the MF and DTMF processor44 within the architecture of FIG. 2 is determined by U52, U53, U51, U9and U26. When the MF and DTMF processor 54 receives data from themicroprocessor, the data is ready to be read.

FIGS. 22A and B are described as follows. FIG. 22A contains the U2322101 audio matrix switch which routes the received and transmitted X.25transmission formatted pages to the respective trunk. The multiplex MFencoder and decoder is also routed to the respective trunk via the audioswitch. The U24 3501 MF encoder and the U8 3101 MF decoder are underdirect microprocessor control. The output level of the 3501 encoder isfixed by resistor R5. The 3501 encoder is capable of sending R1 and R2tone subsets. The voice messaging synthesizer U41 5205 is controlled bythe U20 word latch. The word latch addresses the specific areas of theROM word memories U6 and U7 and is transferred by the U17 4019 switch tothe 5205 voice messaging synthesizer. Address counter U38 sends countsfrom the starting address set by the U21 HC 273, word latch until the"END WORD" gate U47 detects completion of the word. The word latch isthen cleared and the new word may be received from the microprocessor.

4. Data Module Processor 32

The data module processor (DMP) 32 performs several functions. A firstfunction is to interface with the system 10 via the communication path20 between a local switch 12 and the lata switch 14. A second functionis processing of input and output communications which involve the X.25transmission protocol. Input packets of pages, which are in the X.25transmission protocol, are received over the communication link 20 fromthe lata switch 14 or from the telephone trunk 28, as explained above,are stripped of the X.25 transmission protocol down to the fifth levelas explained with reference to FIG. 31 below and converted into ASCIIcode for processing by the CPU 50. The DMP 32 converts ASCII encodedpages received from the outbound lata buffer 82 of the RAM 48, which areintended for transmission to the lata switch 14 over the communicationlink 20, to the hybrid code described below and formats them into X.25protocol with the X.25 protocol being identical to that described belowwith reference to FIG. 31. Furthermore, the DMP 32 contains buffers forstorage of ASCII coded pages which are sent to the RAM 48 and storagefor packets of pages which are forwarded to the data output 34 fortransmission to the associated lata switch 14.

FIGS. 23(A and B)-25(A and B) illustrate a preferred embodiment of thedata module processor 32. Integrated circuits are identified by theirindustry or manufacturer's designation. A control program for the datamodule processor 32 is set forth in the Microfiche Appendix. The controlprogram for the DMP 32 is programmable by input from the keyboard 36 toalter its function to perform the inputting of data for any one of thesublocal, local, lata and hub switches.

The DMP 32 has two X.25 encoder/decoder sets capable of receiving andtransmitting X.25 encoded packets from the network 10. An audio matrixis provided on each of a pair of trunk boards routing the packets in theX.25 transmission protocol. Two modems are provided for the interchangeof system data. The resident microprocessor U7 and random access memoryU5 and U6 process and store packets of pages. The processing includesthe above-described stripping of X.25 transmission protocol from packetsof pages and conversion of characters from the hybrid code describedbelow to ASCII and from ASCII to the hybrid code with the X.25transmission protocol being added. The DMP 32 also provides temporarybuffering of disassembled pages prior to transmission to the buffers 80and 84 of the RAM 48 and temporary buffering of packets of pages priorto transmission to the data output 34.

With reference to FIGS. 23A and B, the resident microprocessor setconsists of the CPU (U7-6502), RAM memory (U5,U6-6164), and the 27128EPROM (U4). All microprocessor address lines are buffered(U8,U9-74HC541) and a data bus buffer U10 (74HC245) is provided. Memorybank decoding is accomplished by U12, with the HC138 being one of eightdecoders. The memory decoder partitions the 64K of memory into 8 banks.Two banks (16K) are utilized for stored program access (EPROM) and twobanks are used for random access memory (16K RAM). Two banks areutilized for the X.25 encoder/decoder circuits and the remaining twobanks for the host processor read/write registers.

With reference to FIG. 24A, the host processor interface consists ofthree write registers (U40--interrupt, U31--TX data, and U32--command)and four read registers (U27, U28, U29, and U30). Each register isindividually addressed in a fashion identical to an 8255 serial port.Memory address decoding is accomplished by a jumper field and decoderU21 (74HC154).

The U7 microprocessor receives clock pulses from divider U33 (74HC74). Aresident watchdog timer U37 (74HC123) monitors processor activity andalerts the host CPU 50 in the event of a catastrophic failure.

With reference to FIG. 23B, X.25, packet assembly/disassembly isaccomplished by the U42, U43 (68560) processors. The 68560 processorscontrol the 3105 modems U14-U15 (FIG. 24B). The clock is derived fromU34 (FIG. 23B) and the modems receive the clock from U35 (FIG. 24B).Amplifiers U17 and U18 (FIG. 24B) provide the necessary gain andbuffering to receive and send modem tones. Jumper straps select two ofthe four external paths for the modems.

Modem receiver bias and carrier detect levels are set via potentiometersVR5, VR6, VR7, VR8 of FIG. 24B.

5. Other Components

The keyboard and monitor 36, printer 38, floppy and hard drive disks 40,modem 42, ROM 46 and RAM 48 are of conventional construction. The ROMmemory 46 is used for support of the CPU 50. The RAM 48 stores thesubscriber base, which is described below with reference to FIG. 3, andthe current version of the operating program for the CPU 50. The disks40 store the stored program to permit updates to be made to the currentprogram stored in the RAM 48. The printer 38 is used for generating theportion of the overall billing information for the network 10 which isto be allocated to the local paging service 18. The keyboard and monitor36 permit the entry of information into the local switch 12 and thedisplay of communications to and from the local switch 12.

6. Memory Map of Local Switch

FIG. 3 illustrates a memory map of the RAM 48. The RAM 48 has four mainstorage areas which are the subscriber files 54, frequency files 56,lata buffers 58 and local buffers 60. It should be understood that inFIG. 3 a number in parenthesis illustrates a number present in apreferred embodiment of the invention, but in the more general case anyvariable number within the scope of the present invention is indicatedby a letter.

Each local switch 12 is allocated a capacity of, for example, 10,000subscribers which are identified by a four-digit code stored in field 62of the subscriber files 54.

Field 64 stores the subscriber's local telephone number within the areacode serviced by the lata switch 14 having jurisdiction.

Field 66 is the subscriber's paging receiver identification code whichuniquely identifies the subscriber and the paging receiver of thesubscriber which is to receive pages throughout the network 10. Thepaging receiver identification code in a preferred embodiment consistsof 8 digits with the four most significant digits geographicallyrepresenting the area serviced by the associated lata switch 14 (countrycode as the most significant digit followed sequentially by area or citycode lesser significant digits) and the four least significant digitsbeing digits assigned to identify 10,000 subscribers within thejurisdiction of the local switch. The capacity of the system 10 is 100million subscribers with the eight digit identification code. The leastsignificant numbers of the identification code define subscribers of aspecific local switch 12 within the jurisdiction of the lata switch 14.

Field 68 stores the service options which each subscriber may choose tohave provided by the local paging service 18. The service optionscontrol the commands discussed below, which are used with pages sent tothe paging receivers. The main CPU 50 interrogates the particularsubscriber file identified by the identification code inputted with therequest for a page by telephone trunks 26 or 28, causes storage of thepage, determines the destination(s) of the page and the appropriatesystem command to be used to transmit the page. It should be understoodthat the service options may be dynamically programmed through voiceprompted communications over the telephone trunk lines 28 with the localswitch 12 and through telephone calls to the lata switch 14 by trunk 26as described below.

The service options are described as follows. The service option "a" isfor no service which is a condition when an active subscriber does notwish to receive any pages such as may occur when the subscriber is onvacation or is otherwise desirous of not being paged for a period oftime but does not wish to be removed from the subscriber base of thesystem. The service option "b" is for pages to be broadcast only by thetransmitter 15 of the local paging service 18. The local service optionhas two suboptions (not illustrated) which permit the selection ofnumeric character transmission (A3 and C3 commands discussed below) andthe selection of alphanumeric character transmission (A4 and C4 commandsdiscussed below). The service option "c" is for regional service whichis for pages to be broadcast throughout all of the local paging services18 which are within its lata switch jurisdiction. The service option "d"is for national paging which is for pages to be broadcast from the localswitch 12 to one or more lata switches 14 other than the lata switchhaving jurisdiction over the local switch 12. While not illustrated, aninternational service option may be added. The regional, national andinternational service options permit the selection of two suboptions(not illustrated) of numeric and alphanumeric character transmission(A5,C5,A6,C6 commands discussed below). The service option "e" is for arepeat of pages for any of the "b", "c" or "d" service options so that apage is broadcast more than once. The service option "f" is for dataservice which causes the page to be stored in a specified section ofmemory such as sections 11-14 of the RAM (60) described in theabove-referenced patent application filed on Oct. 20, 1987. It should beunderstood that reference to a part of a paging receiver in parenthesisrefers to a part in the drawings of the above-referenced applicationfiled on Oct. 29, 1987. The service option "g" is for external dataservice which commands the paging receiver to output the page to theexternal data port (67) of the paging receiver disclosed in theabove-referenced patent application filed on Oct. 20, 1987. This optionpermits the paging receiver to support peripheral devices to provide awide range of data services. Although not illustrated, the serviceoptions may further include sublocal and group paging as discussedbelow. Sublocal paging is discussed below with reference to FIG. 28.Group paging is paging where a specified group of paging receiversreceive pages on the local level by the paging receiver being programmedto turn on when a destination code is sent as the first character of theidentification code accompanying the page as described below.

The following additional fields are provided. The fifth field 70 is thesubscriber's name and the subscriber's specified account number. Thesixth field 72 is the subscriber's account number entry for purposes ofinterval billing by the local paging service 18. The seventh field 74 isthe subscriber's page count (local, regional or national) which is atotal of the number of pages made in a billing period. The eighth field76 is the total number of data characters sent during the billingperiod.

The ninth field 78 is the destination (area code(s)) of each of thepages. For local service, there is no area code specified. For regionalservice, the area code of the associated lata switch 14 havingjurisdiction over the local switch 12 is specified and for national andinternational service, one or more area codes or other geographicidentification identifying lata switches 14 other than the lata switchhaving jurisdiction over the local switch are specified. Forinternational service, a country code may be used to identify lataswitches 14 within a particular country. Any number of area codes may bespecified but in a preferred embodiment of the invention, three areacodes is a maximum number of lata switches 14 which may be specified asregions to receive pages from the local switch 12.

The above-referenced description describes the first file of the n(10,000) possible subscriber files stored in the subscriber files 54. Itshould be understood that the other subscriber files have the sameconfiguration. Access to the subscriber file is obtained by a voiceprompted message requiring the inputting of a secret code which ifinputted correctly is followed by voice prompted requests requestingspecification of the information of the subscriber file to be changed.

The frequency files 56 perform an important part in the functioning ofthe present invention. The frequency files 56 contain n possible latafiles with each individual file identifying up to, for example, 15four-digit numbers that represent broadcast channels available withinthe service area of a lata switch 14. Thus, each of the individual lataswitches 14 in the network 10 will have a separate frequency file whichidentifies all of the channels which are available to transmit pagesfrom the transmitters 15 associated with the local paging services 18under the jurisdiction of that lata switch 14. The channels are storedas a four-digit number in a hexadecimal numbering system which requiresonly four digits of space. The tables of the frequency files may beaccessed from the keyboard 36 or the modem 42. A file containing allzeros (no channel) will cause an invalid area code message to bereturned to a subscriber attempting to reprogram service areas. Aflowchart of the usage of the frequency files 56 by the system isdescribed with reference to FIG. 13 below. However, it should beunderstood that the frequency files are the source of channels which areutilized by the channel programming command discussed below to programeach paging receiver for operation in each lata switch jurisdiction andthe local switch jurisdiction. For example, a paging receiver which isto be serviced by only a single local paging service 18 may beprogrammed to receive only a single or a number of channels up to thenumber of channels used by that local paging service. Furthermore, forregional service or national service, the frequency files are used toprogram the paging receiver to receive pages from the channels used bythe local paging services 18 within the designated area codesrepresentative of the service areas serviced by the lata switches 14.Furthermore, if a paging receiver is to be programmed to receivemessages in a particular area serviced by a lata switch 14 as aconsequence of the subscriber travelling, the channel programmingcommand utilizes the channels stored in the file number corresponding tothe jurisdiction of the lata switch in the area to which the subscriberis to travel, to dynamically program the channel(s) which the pagingreceiver is to receive in that area. For service in a local region, thefrequency files are used as a source of channels to be used by thechannel programming command to dynamically shift the channels on whichthe paging receiver is to receive a page to adjust the channels used inthe broadcast area used by the local paging service 18 associated withthe local switch 12 based on the amount of paging traffic on eachchannel and to further provide a source of channels which are to be usedfor specialized services for transmitting particular types ofinformation to particular subscribers such as, but not limited to stockquotations.

The lata buffers 58 consist of an inbound lata buffer 80 and an outboundlata buffer 82. The inbound lata buffer 80 functions to receive pagescoded in ASCII which have been processed by the data module processor 32to strip them of the X.25 transmission protocol used for transmittingpages from the lata switch 14 to the local switch 12 and converted fromthe hybrid code described below to ASCII. Pages which are initiallystored in the inbound lata buffer 80 are processed by the CPU 50 fordestination and are either for broadcast by the associated local pagingservice 18 in which case they are ultimately stored in the appropriateidentification code buffer 86 which matches the least significant digitof the identification code contained with the page or in the outboundlata buffer 82 if the page is a page which has originated from one ofthe lata switches 14 by calling on the telephone trunk 26 and which hasa final destination which is determined by the field 78 of thesubscriber file 54 as described below.

The local buffers 60 are comprised of an inbound pager buffer 84 forreceiving all local inbound pages which originate from the trunk line 28which is connected to the local switch 12 and a plurality ofidentification code buffers 86 which are each individually assigned tostore outbound pages with a particular least significant identificationcode digit of the number base used for the subscriber identificationcode which are to be transmitted to a local paging receiver. All of thereceived pages from the local switch 12 are initially stored in thebuffer 84. Each of the individual identification code buffers 86 storespages for broadcast by the local paging service 18 in batches which aregrouped by the least significant digit of the subscriber identificationcode received with the page after sorting by the CPU 50. In other words,the least significant digit of the subscriber identification code withina page for broadcast by a local paging service 18 determines in which ofthe identification code buffers 86 the page is stored. For example, ifthe last digit of the identification code of a page for broadcast by thelocal paging service 18 ends in the digit 0, the page is stored in theidentification code buffer identified by "0".

7. CPU 50

The main functions of the CPU 50 are (1) to determine and add areadestinations to each page received from the telephone trunk 28 and thelata switches 14 without any specified area destination to create a pagefor each area destination specified by the service option field 68 andarea destination field 78 obtained by interrogation of the subscriberfile matching the identification code contained in the page, (2) to addone or more system commands to each page created from interrogation ofthe subscriber file, (3) to process each page received from the network10 and each page created by the interrogation of the subscriber file byarea destination, (4) to store each page processed by area destinationin the corresponding storage areas of the RAM 48 as discussed above, and(5) to control the outputting of the stored pages from the RAM 48 forfurther processing by the data module processor 32 or the data output34.

Each of the pages created by the CPU 50 has four fields which are (1)the paging receiver identification code, (2) an area destination in thenetwork and if the page is for transmission by only the local pagingservice 18 the area destination field is left blank, (3) one or moresystem commands specifying the function(s) to be performed by the pagingreceiver receiving the page and (4) the text of the page. These fieldsare discussed below with reference to FIG. 31.

The CPU 50 is programmed to output the groups of pages which are storedin the buffers 82 and 86 whenever either one of two conditions occurwhich are (1) the buffers are approaching a percentage of their maximumstorage capacity measured in characters which should not be exceeded toavoid overflow of the buffers, or (2) pages have not been outputtedwithin an immediately past time interval of a predetermined length.Overflow causes the issuance of a busy tone to a caller wishing to placea page or after a predetermined time interval such as 15 minutes haselapsed, whichever comes first, to avoid a long delay between thecalling in of a page and its actual transmission. The maximum percentageof the overall storage capacity of the buffers 82 and 86 which may beutilized before requiring transmission to avoid overflow is programmablefrom the keyboard 36. Furthermore, the size of the buffers 80, 82, 84and 86 is programmable from the keyboard 36.

B. Lata Switch 14

1. Architecture

FIG. 4 illustrates a functional block diagram of a lata switch 14. Itshould be understood that the block diagram of the lata switch 14 issimilar to the block diagram of the lata switch 12 described above withreference to FIG. 2. Identical parts in FIGS. 2 and 4 are identified bylike reference numerals and are not discussed herein except to theextent necessary to point out the differences. Furthermore, it should beunderstood that the circuits discussed above with reference to FIGS.14(A and B)-25(A and B) are utilized for implementing the lata switch 14with the page being received and transmitted by the data input 30 anddata output 34 being different and further with the operating programfor the CPU 50 being different to produce the correct functioning of thecircuitry of FIGS. 14(A and B)-25(A and B) as a lata switch 14 with thechanges being implemented by inputs from keyboard 36. The data input 30has two high speed X.25 protocol ports for respectively receivingpackets from each of the local switches 12 associated with the lataswitch 14 and packets from an associated hub switch 16. However itshould be understood that the number of ports may vary without departingfrom the invention. Furthermore, the data input 30 does not function todisassemble low speed manual and automatic telephone enteredcommunications as is the case with the data input 30 of the local switch12 in view of the fact that all communications received by the datainput 30 are in the X.25 transmission protocol. The data input transmitsboth X.25 port inputs directly to the data module processor 32. The datamodule processor 32 strips the X.25 protocol from the received packetsof pages from the local switches 12 over which it has jurisdiction andfrom the hub switch 16 having jurisdiction over it and converts thehybrid code described below which is preferably utilized with the X.25transmission formatted packets of pages into ASCII and transmits theASCII coded pages to the hub buffer 100 and local inbound pager buffer102. Pages, which are periodically outputted from the outbound pagesbuffers 98 and 104, are processed by the data module processor 32 toconvert them from ASCII to the hybrid code discussed below and areformatted into the X.25 transmission protocol as discussed below withreference to FIG. 31. The printer 38 functions to generate billinginformation for pages which are distributed to the local switches 12which are within the jurisdiction of the lata switch 14. The CPU 50controls the periodic outputting of pages stored in the RAM 48 from theoutbound hub buffer 98 and outbound local buffers 104 to the data moduleprocessor 32 for code conversion, protocol formatting and transmissionto the associated hub switch 16 or the associated local switches 12 viathe data output 34 as discussed below when the buffers are storing atleast a predetermined percentage (e.g. 70%) of their capacity to avoidloss of pages from overflow or if a transmission of packets from eachbuffer has not occurred within a predetermined time in a manneranalogous to buffers 82 and 86, discussed above. The predeterminedpercentage and the capacity of the buffers 98, 100, 102 and 104 isprogrammable by the keyboard 36.

2. Memory Map

FIG. 5 is a memory map of the random access memory 48 of the lata switch14. The RAM 48 has three main areas and two optional areas. The threemain areas are hub buffers 88, local buffers 90 and a lataidentification code (ID) memory 92. The optional memory areas are an allcall buffer 94 for storing nationwide pages received from the hub switch16 which are to be transmitted to all of the local switches 12 under thejurisdiction of the lata switch 14 and an all call buffer 96 whichstores pages received from one of the local switches which are to betransmitted to all of the local switches 12 under the jurisdiction ofthe lata switch 14.

The hub buffers 88 are an outbound hub buffer 98 and an inbound hubbuffer 100. The outbound hub buffer stores pages to be periodicallytransmitted to the hub switch 16 having jurisdiction over the lataswitch under the control of the CPU 50. The inbound hub buffer 100stores pages which are periodically received from the associated hubswitch 16 via storage in a buffer of the data module processor 32.

The local buffers 90 are comprised of an inbound local buffer 102 whichstores groups of inbound pages received from the local switches 12 and aplurality of outbound local buffers 104 each of which store groups ofpages which are to be transmitted periodically to a specific one of thelocal switches with a separate outbound local buffer being provided foreach of the local switches under the jurisdiction of the lata switch 14.The CPU 50 processes each of the pages which is received in the inboundbuffers 100 and 102 by destination and causes storage in the outboundbuffers 98 and 104 which is associated with the destination of the page.

The lata identification code memory 92 stores the subscriberidentification numbers of all of the subscribers which are associatedwith each of the local switches 12 within its jurisdiction. The lataidentification code memory 92 is used for determining the local switchwhich stores a subscriber file of the subscriber used for pages whichare inputted to the system from a direct call by telephone trunk 26 to alata switch 14 or from a direct call by telephone trunk 26 to a lataswitch by a subscriber to program the reception area of pages bychanging the destination 78 of the pages. The lata identification codememory 92 may be organized by subscriber identification codes which arewithin the jurisdiction of each local switch 12 so that the matching ofan identification code of a page inputted to the lata switch 14 in thelata identification code memory 92 provides the location of theparticular local switch which stores the subscriber file 54 of thatsubscriber.

In order to avoid having to provide additional storage space in each ofthe outbound local buffers 104, the optional all call buffer 94 may beprovided to store a single page, received from the hub switch 16 havingjurisdiction over the lata switch 14, which is to be transmitted to eachof the local switches 12. Similarly, the optional all call buffer 96 maybe provided for receiving pages from an individual local switch 12 whichare to be transmitted to all of the local switches 12 within thejurisdiction of the lata switch 14.

The CPU 50 controls the telephone trunk 26 between the lata switch 14and the caller requesting a numerical or alphanumerical character pageover the telephone trunk with voice prompted messages by placing adirect phone call to the lata switch. For pages or requests to reprogramthe subscriber file 54 which are made to a lata switch 14 over telephonetrunk 26 which require access to a subscriber file outside thejurisdiction of the lata switch, the CPU 50 makes a page contained in apacket having an area destination identified by the four mostsignificant digits of the identification code inputted to the lataswitch 14 preceded by the identification code of the paging receiver toreceive the page, preceded by the geographical area identification ofthe lata switch receiving the call to originate a page or to program thesubscriber file which is transmitted by the network 10 to the specifiedarea destination. For pages to be billed to subscribers stored in thesubscriber file 54 of a local switch 12 within the jurisdiction of thelata switch 14 or requests to program the subscriber file 54, the CPU 50makes a packet having an area destination of the local switch 12 withinits jurisdiction which stores the subscriber identification code asdetermined by interrogation of the lata identification code buffer 92 bythe CPU. The ultimate destination of a page is determined by thedestination field 78 of the subscriber file 54 matching theidentification code of the paging receiver either within or outside thejurisdiction of the lata switch that is called in over telephone trunk26. The local switch 12 containing the subscriber file 54 creates theone or more pages in accordance with the information in the subscriberfile including the adding of destination(s) and the appropriate command.Transmission of the pages created by the local switch 12 in response toa call to a lata switch 14 is identical to the transmission of pagesoriginating at the local switch 12 by the placing of a telephone call ontelephone trunk 28. In the case of requesting programming of thesubscriber's file 54, the caller must in response to a voice promptedmessage enter a four-digit secret identification code to obtain accessto the subscriber file with voice prompted messages being supplied underthe control of the CPU 50 to control the input of programminginformation from the subscriber. To request a page by calling the lataswitch 14, the caller will receive a voice prompted message to enter thesubscriber identification code and then the appropriate numeric oralphanumeric character page.

C. Hub Switch 16

1. Architecture

FIG. 6 is a functional block diagram of the hub switch 16. It should beunderstood that the block diagram of the hub switch 16 is similar to theblock diagram of the local and lata switches described with reference toFIGS. 2 and 4. Like parts in FIGS. 2, 4 and 6 are identified by likereference numerals and further only those differences between thesubject matter of FIG. 2 and FIG. 6 are discussed which are necessaryfor understanding the operation of the hub switch 16. Furthermore, itshould be understood that the programming for controlling each of theprocessors including the central processing unit 50 is set forth in theaforementioned Microfiche Appendix with variations in the programmingbeing implemented by inputs from the keyboard 36 to cause the program tocontrol a hub switch 16. The circuits for implementing the data input30, data module processor 32, data output 34 and MF and DTMF processor44 are illustrated in FIGS. 14(A and B)-25(A and B) discussed above. Thedata input 30 receives X.25 encoded packets on input ports respectivelyfrom associated lata switches 14 and from hub switches 16 which areforwarded to the data module processor 32 for processing. The datamodule processor 32 functions to strip the X.25 transmission protocoland convert the character in the hybrid code described below into ASCIIcoded pages. Pages received from lata switches 14 within thejurisdiction of the hub switch 16 are addressed by the data moduleprocessor 32 for storage in a corresponding inbound lata buffer 118described below with respect to FIG. 7. Similarly, pages received fromother hub switches 16 are addressed by the data module processor 32 forstorage in the corresponding inbound hub buffer 114 described below withrespect to FIG. 7. The CPU 50 processes each page stored in the inboundbuffers 114 or 118 to determine its destination and causes its storagein the outbound buffers 116 and 120 which correspond to the destinationof the page. The CPU 50 periodically outputs the stored pages from theoutbound buffers 116 and 120 when either the pages stored in the buffers114 and 118 reaches a predetermined percentage of their maximum capacityto avoid an overflow of pages which could cause a loss of pages or whena transmission of pages from each of the buffers 116 and 120 has notoccurred during a predetermined time interval. The predeterminedpercentage and the size of the buffers 114, 116, 118 and 120 isprogrammable by input from the keyboard 36. The data module processor 32also functions to convert the pages from ASCII code to the hybrid codeand formats the page into the X.25 transmission protocol described belowwith reference to FIG. 7, which are periodically outputted from theoutbound hub buffers 116 and the outbound lata buffers 120 of RAM 48described below with reference to FIG. 7. The data output 34 outputs thepackets of pages received from the data module processor 32 to theappropriate output port(s) depending upon the destination of the packetsof pages. The printer 38 functions to produce a record for billing ofsubscribers for pages transmitted through the hub switch 16.

2. Memory Map

FIG. 7 is a memory map of the RAM 48 of the hub switch 16. The hubswitch memory map is comprised of four main parts which are hub buffers106, lata buffers 108, lata code tables 110 and hub routing codes 112.The hub buffers 106 are comprised of a plurality of inbound hub buffers114 which correspond in number to the number of other hub switches 1 inthe network 10 which have direct connection to the hub switch and acorresponding number of outbound hub buffers 116. The individual inboundhub buffers 114 each store pages received from one of the hub switches16 with pages received from each adjacent hub switch 16 being stored inonly a single one of the inbound hub buffers 114. Similarly, pages whichare to be transmitted to another hub switch 16 are stored in theoutbound hub buffer 116 which is associated with the destination hubswitch to which they are being transmitted with all pages which are tobe routed to a single hub switch being stored in a corresponding one ofthe outbound hub buffers 116 with a separate hub buffer being associatedwith each hub switch to which pages are directly transmitted. The latabuffers 108 are comprised of a plurality of inbound lata buffers 118which correspond to the number of lata switches 1 under the jurisdictionof the hub switch 16. The inbound lata buffers 118 store all of thepages received from the lata switches 14 under the jurisdiction of thehub switch 16. The outbound lata buffers 120 correspond in number to thelata switches 14 under the jurisdiction of the hub switch 16 with aseparate lata buffer being associated with each of the lata switches.The outbound lata buffers 120 store groups of pages to be periodicallytransmitted to their associated lata switch 14. Pages which are storedin the inbound hub buffers 114 are processed by destination by the CPU50 and stored in either the outbound hub buffer 116, which is thedestination of the pages if the pages are not to be received by a lataswitch 14 under the jurisdiction of the hub switch 16, or in one or moreof the outbound lata buffers 120 if the destination of the packets ofpages received from another hub switch 16 is a lata switch under thejurisdiction of the hub switch 16. The CPU 50 also processes the pagesstored in the inbound lata buffers 118 according to their destinationand causes their storage in either the outbound hub buffers 116 if thepages are to be sent to a lata switch 14 outside of the jurisdiction ofthe hub switch 16 or to one or more of the outbound lata switches 120 ifthe pages are to be received by one or more lata switches 14 under thejurisdiction of the hub switch 16.

The lata code tables 110 store each of the lata (telephone area or othergeographic identifier) codes 122 under the jurisdiction of the hubswitch 16 which are utilized by the comparison performed by the CPU 50with the pages stored in the inbound hub buffers 114 and inbound latabuffers 118 to determine in which of the outbound hub buffers 116 oroutbound lata buffers 120 the pages should be stored. Each separate latacode 122 corresponds to the geographical identification of the lataswitch 14 which in the preferred embodiment is the telephone area codeof a lata switch's jurisdiction.

The routing codes 112 determine the transmission routes to other hubswitches on a priority basis to which a packet of pages should be sentwhich are not intended for a lata switch 14 within the jurisdiction ofthe hub switch 16. It should be understood that a number of factors maybe considered in choosing the priority of a route to be used to transmita page from one hub switch 16 to another hub switch. It would appear onfirst analysis that a direct first hub switch to second hub switch routewould be best but often the switching overhead of routing a packetthrough one or more intermediate switches is more than compensated forby the efficiency of a route having one or more intermediate hubswitches by adding additional pages which are inputted to the one ormore intermediate hub switch(es) to the packets of pages beingtransmitted to the second hub switch. The CPU 50 compares thedestination of the groups of pages stored in the inbound hub buffers 114and the inbound lata buffers 118 to determine if these pages should berouted to another hub switch 16. The hub routing codes 112 are referredto by default when a match is not found by the CPU 50 in comparing thedestination of the pages stored in the inbound hub buffers 114 andinbound lata buffers 118 with the codes stored in the lata code tables110. Each page stored in the inbound hub buffer 114 and inbound latabuffers 118 is processed by destination by the CPU 50 and caused to bestored in the outbound buffers 116 and 120 which correspond to itsdestination. Each individual hub routing code contains the hub switchdestination priorities for pages to be sent to a single lata switch 14outside the jurisdiction of the hub switch 16. For example, for the lataswitch 14 having jurisdiction over area code 312, the hub routing code134 determines the priorities in descending order from the highestpriority to the lowest priority such that the highest priority hub wouldbe #1 followed by #2-#6.

VI. Local Switch Operation

FIG. 8 is a flowchart of the operation of the local switch 12 inprocessing pages received from either a local telephone input bytelephone trunk 28 or from the associated lata switch 14 overcommunication link 20. The processing starts at point 130 and proceedsto point 132 where a packet of pages formatted in the X.25 transmissionprotocol received from an associated lata switch 14 over transmissionlink 20 or manual DTMF tone numeric coded characters, manual DTMFalphanumeric encoded characters, low speed automatic telephone DTMFcoded alphanumeric characters or alphanumeric coded characters formattedin X.25 transmission protocol from a high speed data device overtelephone trunk 28 is received by data input 30. The data input decodesthe pages which are received from the telephone port 28 to determinewhich of the four possible types of inputs the page is. The decoding isperformed by detecting if any of the particular command headersdiscussed above is included within the page. The header or absencethereof within each page controls the processing rate by themicroprocessor of the data input 30 as described below. The data input30 determines if the received data is encoded in a high speed X.25protocol or in the protocol used for manual or low speed automatictelephone entry as indicated by decision point 134. Data inputs whichare not in X.25 transmission protocol are stripped of any transmissionprotocol by the data input 30, converted from the code used fortransmission to the data input 30 to ASCII and forwarded to the inboundpages buffer 84 as indicated at point 142. If the received packet ofpages is determined to be an X.25 protocol, the packet of pages isforwarded to the data module processor 32 where the X.25 encodingprotocol is stripped and the pages are converted into ASCII code fromthe code used for transmission which preferably is the hybrid codedescribed below. The data module processor 32 further places a databuffer address on the disassembled pages and causes them to be forwardedto the inbound lata buffer 80 or to the inbound pages buffer 84 if theywere received in X.25 protocol over the telephone trunk 28 as indicatedat point 138. The CPU 50 processes the pages stored in the inbound latabuffer 80 by destination to determine if the page is to be placed in theidentification code buffers 86 or is an "all entry" page originatingfrom another lata switch 14 by a telephone call over telephone trunk 26requiring processing by the CPU 50 to determine its final destination bylookup in the subscriber file 54 storing the identification codecontained with the page to determine the destination lata switch(es) 14.The CPU 50 performs destination analysis of the pages by matching thepage identification code contained within the page with thecorresponding subscriber identification code contained in the subscriberfile 54 and interrogation of the destination field 78 to determine ifthe page is to be broadcast to the local paging service 18 or is to besent back to the network via the lata switch 14 having jurisdiction overit for transmission to the destination specified by field 78. Thedestination analysis processing by the data input 30 is indicated atpoint 142 and the determination of whether the page is local or not isindicated at decision point 144. If it is determined that the page isintended for purely local broadcast at decision point 144, processingproceeds to point 146 where all pages received from the lata switch 14which are determined to not be pages made by local telephone call ontelephone trunk 26 to a lata switch 14 and further all pages telephonedto the input 30 by telephone trunk 28 which are determined to bebroadcast by the local paging service 18 are processed by the CPU 50 byprocessing the contents of the inbound lata buffer 80 and the localinbound pages local buffer 84. The CPU 50 determines the leastsignificant digit of the paging receiver identification code containedin the page and causes storage in the buffer of the identification codebuffers 86 which is assigned to store pages which are determined to havea least significant digit which agrees with the determined leastsignificant digit. If the pages originating by telephone call to thedata input 30 are determined to not be for local destination at decisionpoint 144, processing by the CPU 50 occurs at point 148 where the CPUadds the destination area code specified in field 78 of the subscriberfile 54, adds the command to the page which is utilized for itstransmission by the system 10 by interrogation of the service options 68and causes storage in the outbound lata buffer 82. At point 150, the CPUperiodically transmits pages (1) stored in the outbound lata buffer 82to the data module processor 32 for conversion of the characters fromASCII code to another code, which preferably is the hybrid codedescribed below, and the addition of the X.25 transmission protocol andtransmission to the data output 34, and (2) stored in buffers 86 to thedata output for code conversion from ASCII to another code whichpreferably is the hybrid code discussed below. At point 152, the dataoutput 34 transmits the X.25 transmission formatted packets of pages tothe lata switch 14 by the transmission link 20 and transmits batches ofthe pages encoded in hybrid code, without the X.25 transmissionprotocol, to the local paging service 18 by the communications link 22for transmission by transmitter 15.

VII. Lata Switch Operation

FIG. 9 is a flowchart illustrating the processing of pages by the lataswitch 14. Processing proceeds from starting point 160 to point 162where the data input 30 of the lata switch 14 receives X.25 transmissionformatted packets of pages from either an associated local switch 12 inits jurisdiction or from the hub switch 16 having jurisdiction over it.The received packets of pages are forwarded to the data module processor32 which strips the X.25 transmission protocol and converts thecharacters of the pages from the code used for transmission, whichpreferably is the hybrid code discussed below, to ASCII code used by thecentral processing unit 50 and applies suitable addressing to forwardthe packets of pages to either the inbound hub buffer 100 for storingpages received from the hub switch 16 or to the inbound local buffer 102for storing pages received from local switches 12. The functioning ofthe data module processor 32 is illustrated at point 164. The CPU 50determines if the packets of pages stored in the buffers 100 and 102 aredestined for the lata switch 14 as illustrated at decision point 166. Ifnone of the pages are destined for the lata switch 14, each page iscaused by the CPU 50 to be stored in the outbound hub buffer 98 forsubsequent transmission to the associated hub switch 16 as indicated atpoint 167. If, on the other hand, pages in either the buffers 100 or 102are determined to be destined for transmission to a local switch 12, theCPU 50 causes the storage of each page in each of the local outboundbuffers 104 as indicated at point 168. It should be understood that thedestination of each page that is determined by the lata switch 14 to beto all of the local switches under its jurisdiction could alternativelybe determined to be a particular single local switch in which case thepage would be stored in a single one of the outbound local buffers 102which is associated with the destination local switch 12. The onlydisadvantage of this procedure is that it requires further intelligenceto be specified in the destination stored in the destination field 78for all pages which are to be transmitted from a single local switch 12to another local switch. The CPU 50 periodically reads out the pagesstored in the local buffers 104 and hub buffer 98 and transmits them tothe data module processor 32 for processing as indicated at point 170.The data module processor 32 receives the pages outputted from theoutbound hub buffer 98 and the local outbound buffers 102, converts themfrom ASCII to the code to be used to encode characters for transmission,which preferably is the hybrid code discussed below, and adds the X.25transmission protocol as indicated at point 174. A determination is madeby the data module processor 32 of the destination of the packet ofpages as indicated at decision point 176. If the destination of thepackets of pages received by the data output 34 is the associated hubswitch 16, the packets are transmitted to the hub switch bycommunication link 20 as indicated at point 178 where processing ofpages destined for the hub switch is complete. If, on the other hand,the destination of the packets of pages is determined to be to the localswitches 12 within the jurisdiction of the lata switch 14, the dataoutput 34 forwards the pages to each of the associated local switches 12under the jurisdiction of the lata switch 14 by communication links 20.Alternatively, as discussed above with respect to point 168, if a singleor a group of local switches 12 less than the total number of switchesunder the jurisdiction of the lata switch 14 has been specified as thedestination of the page, the data output 34 transmits the packet ofpages to the single or plurality of local switches 12 which arespecified as a destination. The functioning of the page output 34 intransmitting a packet of pages to the local switches is indicated atpoint 180.

VIII. Hub Switch Operation

FIG. 10 illustrates a flowchart of the processing of packets of pagesreceived by the hub switch 16. The processing proceeds to point 190where the data input 30 receives packets of pages from either of theports connected to the associated lata switches 14 or from the portsconnected to the associated hub switches 16 as indicated at point 190.The packets are forwarded from the data input 30 to the data moduleprocessor 32 which strips off the X.25 protocol and converts thereceived pages from the hybrid code described below to ASCII code usedby the CPU 50. The data module processor 32 attaches an address to thepackets of pages which are respectively received from the ports from theassociated lata switches 14 and from the ports from the associated hubswitches 16 which is used to address respectively the inbound latabuffers 118 and the inbound hub buffers 114 as indicated at point 192.As indicated at decision point 194, the CPU 50 determines whether or notthe pages stored respectively in the inbound lata buffers 118 and theinbound hub buffers 114 are destined for a lata switch within thejurisdiction of the hub switch 16. If the pages stored in theaforementioned inbound lata buffers 118 and the inbound hub buffers 114are not destined for a lata switch 14, the CPU 50 causes the pages to bestored in the outbound hub buffer 116 associated with the destinationhub switch as indicated at point 196. The aforementioned destinationsare determined by the CPU 50 utilizing the hub routing codes 112 bycomparing the destination of each page with the hub routing code todetermine which hub switch 16 to which the page should be sent. Itshould be noted that each hub routing code 124 contains the priority ofthe hub switches 16 and the transmission paths by which pages destinedfor the destination lata switch 14 are to be transmitted. Thus, asillustrated with reference to FIG. 7, if the destination code of thelata switch 14 is area code 312, the first priority hub switch is number1 with descending priorities being switches 2, 3, 4, 5 and 6. If hubswitch number 16 is busy or malfunctioning as determined by the placingof a call to that hub switch by the data output 34, the CPU 50 utilizesthe routing code for area code 312 to determine the next highestavailable priority hub switch 16 and transmission path by which the pageshould be sent. In this manner, alternative paths which are lessefficient or more expensive are substituted for the most efficient orleast expensive transmission route to another hub switch 16 to maintainoverall system functionality in the event of one or more switches orcomponents failing. If the destination of the page is determined to be alata switch 14 under the jurisdiction of the hub switch 16 as aconsequence of matching the destination with one of the lata codescontained in the lata code table 110, the CPU 50 causes the storage ofthe page in the outbound lata buffer 120 to which it is destined asindicated by point 198. The CPU 50 periodically reads out the pagesstored in the outbound hub buffers 116 and the outbound lata buffers120. The CPU 50 places an address on pages being read out respectivelyfrom the outbound hub buffers 116 and outbound lata buffers 120 whichcauses them to be received in a buffer of the data module processor 32for code conversion and adding of transmission protocol to form intopackets of pages for transmission to the destinations specified by theCPU as indicated by point 200. The data module processor 32 converts theASCII encoded characters to the hybrid code described below and formatsthe pages stored in its buffers with X.25 , transmission protocol toform packets of pages. The particular buffers of the DMP 32 in which thepackets of pages are stored determines from which port the packets areoutputted by the data output 34 to the lata switches 14 under the hubswitches jurisdiction or to the other hub switches 16. A determinationis made by the data module processor 32 of whether the destination ofthe packet of pages is a lata switch 14 as indicated at decision point204 and the packet is transmitted to the data output 34. If thedestination of the packet of pages is not a lata switch 14, the dataoutput 34 transmits the packet of pages to a destination hub switch 16as indicated at point 206. If the destination of the packet isdetermined to be a lata switch 14, the data output 34 transmits thepacket of pages to the destination lata switch as indicated at point208.

IX. System Operation For Processing Pages Originating At A Local Switch

FIG. 11 is a flowchart of the operation of the network 10 in processingpages originating at a local switch 12. The processing proceeds to point220 where a call is placed to the local switch 12 with a page to betransmitted to a paging receiver. The call is placed via the localtelephone trunk 28 and may be either a page consisting of numericalcharacters or a page consisting of alphanumeric characters having thethree input formats described below. As described with reference to FIG.2, the input may be introduced manually by a telephone handset usingDTMF tones or, alternatively, a rotary dial set or from a low speedautomatic input providing alphanumeric characters in coded format orfrom a high speed input in coded format using the X.25 transmissionprotocol. The message includes the subscriber identification code storedin the field 66. The local switch 12 determines if the page is destinedfor broadcast by the associated local paging service 18 or for regionalor national service as determined by the appropriate service optionstored in field 68 of the subscriber file 54. The CPU 50 determines theappropriate level of service by matching the paging receiveridentification code inputted by the local call with the correspondingnumber in the subscriber file 54 and interrogates the service optionsspecified therein in field 68 to determine the command to be used asdescribed below. The operation of the CPU 50 in determining if theservice is local, regional, or national is indicated at decision point222. The page is initially held in the local inbound page buffer 84while this determination is made. If the page is determined to be a pageto be transmitted to a local paging service 18, processing proceeds topoint 224 where the CPU 50 causes storage in the identification codebuffer 86 associated with a digit which agrees with the leastsignificant digit of the inputted paging receiver identification codeand adds the system command to be used. Processing proceeds to point 226where the CPU 50 periodically reads out any pages stored in theindividual ID code buffers 86 to produce groups of one or more pages tobe transmitted to the data output 34 for coding in the hybrid codediscussed below and transmission to the local paging service 18.Thereafter, the individual page is broadcast by the transmitter 15associated with the local paging service 18 as indicated as point 228.If at decision point 222 the page is determined to be one destined for alata switch 14 (regional) or a plurality of lata switches (national),the CPU 50 adds the destination information stored in field 78 of thesubscriber file 54, adds the system command as indicated at point 230and proceeds to store the page in the outbound lata buffer 82 asindicated at point 232. The CPU 50 then forwards the page to the datamodule processor 32 for code conversion from ASCII to the hybrid codedescribed below and formatting in the X.25 transmission format to form apacket of pages and transmission to the data output 34 where it isoutputted to the lata switch 14 as indicated at point 234. The page isreceived by the associated lata switch 14 where a determination is madeif its destination is that particular lata switch jurisdiction asindicated at point 236. If the lata switch 14 determines that the pageis destined for its jurisdiction, the CPU 50 of the lata switch 14causes storage of the page in the outbound local buffers 104 asindicated at point 237. As indicated at point 238, the CPU 50 of thelata switch 14 then periodically outputs the contents of the outboundlocal buffers 104 to the associated data module processor 32 for codeconversion from ASCII to the hybrid code described below and addition ofthe X.25 transmission protocol as described below to form a packet ofpages and forwarding to the data output 34 for transmission to each ofthe local switches 12 in the jurisdiction of the lata switch 14 asindicated at point 238. Processing then proceeds to point 226 asdescribed above. If the lata switch 14 determines that the page is notdestined for its jurisdiction, the CPU 50 causes storage in the outboundhub buffer 98 as indicated at point 240. The CPU 50 then forwards thepages periodically from the hub buffer 98 to the data module processor32 for code conversion from ASCII to the hybrid code described below andfor addition of the X.25 transmission protocol as described below toform a packet of pages and forwarding to data output 34 for transmissionto the hub switch 16 associated with the lata switch 14 as indicated atpoint 242. The hub switch 16 upon receipt of the packet from the lataswitch 14 determines if the pages contained therein are destined for alata switch within its jurisdiction as indicated at decision point 244.If the answer is "yes", the CPU 50 in the hub switch 16 causes the pageto be stored in the outbound lata buffer 120 which is associated withthe lata switch which is the destination of the page as indicated atpoint 246. The CPU 50 of the hub switch 16 then periodically outputs anypages stored in the outbound hub buffer 120 to the data module processor32 for code conversion from ASCII to the hybrid code described below andaddition of the X.25 transmission protocol to form a packet of pages andforwarding to data output 34 where they are forwarded to the destinationlata switch 14 as indicated at point 248. The process then proceeds topoint 237 as described above. If the CPU 50 of the hub switch 16determines that the destination of the page is not within itsjurisdiction, the communication route for the page is determined by thehub routing codes 112 in accordance with the priority information storedtherein. As indicated at point 250, the CPU 50 of the hub switch 16 thencauses storage in the corresponding outbound hub buffer 116 as indicatedat point 252. The CPU 50 periodically causes any pages stored in theoutput hub buffer to be forwarded to the data module processor 32 forcode conversion from ASCII to the hybrid code described below andaddition of the X.25 transmission protocol to form a packet of pages andto the data output 34 for transmission to the designated hub switch 16as indicated at point 254. The processing proceeds back to decisionpoint 244.

X System Operation For Pages Placed by Local Telephone Call to LataSwitch

FIG. 12 illustrates a flowchart of the processing of an "all entry" pagecalled into a lata switch 14 by calling on the telephone trunk 26. Whilethe description of the network's processing of the page called in to alata switch 14 discussed below is not with reference to a request toreprogram a subscriber file 54, it should be understood that theprocessing of requests to reprogram a subscriber file is analogous tothe description below in routing a page to a local switch 12. It shouldbe understood that the page called in on telephone trunk 26 may beeither a purely numeric character page or an alphanumeric character pagereceived with any of the four input formats described above and furthercontains an identification code which is the paging receiver to receivethe page and subscriber identification code. A page originated by alocal phone call to a lata switch 14 includes a message portion precededby the identification code of the paging receiver to receive the pagepreceded by the geographic identification code of the lata switchreceiving the call on telephone trunk 26 to originate a page. Thegeographic code of the lata switch 14 enables a receiving local switch12 to differentiate the page from pages originating at a local switch.The resultant page is formed into a packet and forwarded by the network10 to a local switch 12 where the subscriber file of the subscriberhaving the same subscriber identification code as the identificationcode of the page is stored that is within the jurisdiction of the lataswitch 14 identified by the first four digits of the identification codecontained in the page. The destination information 78 of the subscriberidentified by the subscriber identification code is interrogated by theCPU 50 to determine any area destination(s) of the page in the network.The calling of the lata switch 14 is indicated at point 252. It is notnecessary for the person placing the request for a page to have anyknowledge of the subscriber's location given the fact that thesubscriber and paging receiver identification code called in with the"all entry" page is geographically descriptive of the lata switch 14having jurisdiction over the local switch 12 storing the subscriber file54 which permits the network 10 to forward the page back to the localswitch to determine any area destination(s) to which the age should besent. Processing proceeds to decision point 254 where a determination ismade if the page received by the lata switch 14 has an area destinationwithin the lata switch jurisdiction which is made by comparing theidentification code accompanying the page with the identification codesstored in the lata ID memory 92. If the answer is "yes", processingproceeds to point 256 where the CPU 50 of that lata switch 14 causes thepage to be stored in the outbound local buffer 104 which is associatedwith the particular local switch in which the subscriber file is locatedbased on the above-described comparison of the subscriber identificationcode with the identification codes stored in the lata ID memory 92. TheCPU 50 of the lata switch 14 outputs the page from the buffer 104 to thedata module processor 32 for code conversion from ASCII to the hybridcode described below and formatting of the page in the X.25 transmissionprotocol to form a packet and forwards the packet to the data output 34for transmission to the local switch 12 containing the subscriber fileas indicated at point 258. The local switch 12 receives the packet,disassembles the packet and compares the identification code of thedisassembled page with the identification codes contained in thesubscriber files 54 to identify the particular subscriber file. Uponlocation of the particular subscriber file, the subscriber's destinationfield 78 is interrogated to determine any area destination(s) to whichthe page is to be transmitted as indicated at point 260. The areadestination of the page is then changed by the CPU 50 to anydestination(s) specified by the destination field 78 as indicated atpoint 262 and the system command as dictated by the service option field68 is added to form one or more pages corresponding in number to thenumber of area destinations specified by the service options 68 anddestination area codes 78. The CPU 50 then causes the page to be storedin the outbound lata buffer 82 as indicated at point 264. The page(s) isthen outputted to the data module processor 32 for code conversion fromASCII to the hybrid code discussed below and formatting of the page inthe X.25 transmission protocol to form a packet(s) and forwarding todata output 34 where the packet(s) is transmitted to the lata switch 14having jurisdiction as indicated at point 266. Thereafter, theprocessing proceeds to point 236 of FIG. 11 as described above. If thedetermination is that the area destination of the pages(s) is not withinthe lata switch jurisdiction at decision point 254, processing proceedsto point 257 where the page(s) is stored in the outbound hub buffer 98.The CPU 50 periodically outputs the contents of the hub buffer 98 to thedata module processor 32 for code conversion from ASCII to the hybridcode discussed below and formatting of the page(s) in the X.25transmission protocol to form a packet(s) and forwarding the packet(s)to data output 34 for transmission to the associated hub switch(es) 16as indicated at point 259. Processing proceeds to decision point 261where a determination is made by the hub switch 16 if the destination ofthe page(s) is within the hub switch jurisdiction. If the answer is"yes", the processing proceeds to point 263 where the CPU 50 causesstorage of the page(s) in the outbound lata buffer 120. Thereafter, theCPU 50 periodically outputs the contents of the outbound lata buffer 120to the data module processor 32 for code conversion from ASCII to thehybrid code discussed below and formatting in the X.25 transmissionprotocol to form a packet(s) and forwarding the packet(s) to the dataoutput 34 where the packet(s) is transmitted to the lata switch 14 whichis the destination as indicated at point 265. Processing then proceedsto point 256 as described above. If the answer is "no" at decision point264, processing proceeds to point 267 where the CPU 50 makes adetermination of the transmission route for the page(s) to another hubswitch 16 by use of the hub routing codes 112 to determine the hubswitch to which the page should be forwarded. The CPU 50 then causesstorage in the outbound hub buffer 116 which is the area destinationdetermined by comparison of the destination area code with the hubrouting codes 112 as indicated at point 268. The CPU 50 then causes thepage(s) to be outputted from the outbound hub buffer 116 to the datamodule processor 32 for code conversion from ASCII to the hybrid codediscussed below and formatting in the X.25 transmission protocol to forma packet(s) and forwarding to data output 34 where the packet(s) istransmitted to the adjacent hub switch 16 as indicated at point 270.

XI. Programming of Frequency Band of Paging Receiver

FIG. 13 is a flowchart illustrating the programming of the channelmemory of a paging receiver to receive different channels. Programmingof the channels of a paging receiver may be made by placing either acall to a lata switch 14 by telephone trunk 26 or by local call ontelephone trunk 28. The channel programming command that is transmittedto the paging receiver to accomplish programming of the receptionfrequency is described below. The paging receiver is described in detailin the above-referenced patent applications filed on Oct. 20, 1987. Itshould be understood that the actual programming of channels istransparent to the subscriber or other authorized person requestingprogramming of channels in that the local switch 12 at which thesubscriber's subscriber file 54 is stored automatically issues a pagecommanding the paging receiver having a identification code identical tothe paging receiver identification code stored in field 66 to beprogrammed with channels permitting reception in the new destinationarea(s) specified in field 78 to receive the channels specified in thefrequency files 56 which match the area(s) stored in field 78.Programming the channel by a call to a lata switch 14 proceeds from thestarting point where a caller directly calls a lata switch 14 by placinga local phone call over a telephone trunk 26 such as a 950 exchange toprogram the field 78 for reception in a new area(s). The caller receivesa voice prompted message from the CPU 50 located at the lata switch 14which prompts the caller to enter by means of DTMF codes or by rotarydialing a secret code (four digits) issued to the subscriber and the newarea(s) in which the paging receiver is to receive pages. The secretcode prevents unauthorized access to the subscriber's file 54 maintainedin the local switch 12. This process is identified by reference numeral290. Processing proceeds to decision point 292 where the lata switch 14examines the second, third and fourth most significant digits of thepaging receiver identification code inputted by the caller and comparesthose digits with its region designation to determine if the page isdestined for that particular lata switch 14. The first digit is commonto all paging receivers in a country and therefore is ignored in thisexample. This determination is made by the central processing unit 50comparing the identification code called in with the page with the lataID memory 92 to determine if the identification code matches any one ofthe paging receiver identification codes stored in the lata ID memory.If a match is found, which means that the page destination is located inthe region of the lata switch 14, processing proceeds to point 294 wherethe page is stored in the particular outbound local buffer 104 which isassigned to the particular local switch 12 which contains the subscriberidentification code in its subscriber files 54. Processing proceeds topoint 296 where the lata switch 14 causes the pages stored in the localoutbound buffer 104 to be periodically read out and forwarded to thedata module processor 32 for code conversion from ASCII to the hybridprotocol described below and formatting in the X.25 transmissionprotocol to form a packet and forwarding to output 34 and transmissionto the local switch 12 as indicated. The local switch 12, containing thesubscriber identification code matching that contained in the page whichwas called to the lata switch 14, proceeds to verify that the secretaccess code to the subscriber's file agrees with that subscriber'ssecret access code and enters the new area(s) into the field 78 andlooks up the channels in the frequency files 56 which are assigned tothe new area as indicated at point 298. The CPU 50 then assembles achannel programming command for each new area(s) which has been added tothe field 78 which has a destination of one of the newly added areas asindicated at point 300. The local switch 12 then stores the channelprogramming command(s) in the outbound lata buffer 82 which isperiodically read out under the control of the CPU 50. The CPU 50 thencauses the channel programming commands to be outputted from theoutbound lata buffer 82 to the data module processor 32 for codeconversion from ASCII to the hybrid code described below and formattingin the X.25 transmission protocol to form a packet and forwarding to thedata output 34 for transmission to the associated lata switch 14 asindicated at point 302. Furthermore, although not illustrated, if theservice option field 68 specifies local service, the CPU 50 causes thepage to be assembled as a page to be broadcast locally, stored in theappropriate ID code buffer 86, outputted to the data output 34 andconverted to the hybrid code discussed below and forwarded to the localpaging service 18. Operation then proceeds as described above atdecision point 236 of FIG. 11. If the determination at decision point292 was that the page destination is outside of the jurisdiction of thelata switch 14, processing proceeds to point 304 where the lata switch14 causes storage of the page to be stored in the outbound hub buffer98. The CPU 50 of the lata switch 14 causes the page to be read out ofthe hub page buffer 98 and transmitted to the data module processor 32for code conversion from ASCII to the hybrid code described below andformatting in the X.25 transmission protocol to produce a packet andforwarding to the data output 34 for transmission to the associated hubswitch 16 as indicated at point 306. The hub switch 16 makes thedetermination as indicated at decision point 308 of whether the page hasa destination of a lata switch 14 within the hub region. If the decisionis "yes" at decision point 308, processing proceeds to point 310 wherethe hub switch 16 causes storage of the page in the outbound lata buffer120 which is assigned to the destination lata switch 14. The CPU 50 ofthe hub switch 16 then causes the page to be read out of the lata buffer120 and transmitted to the data module processor 32 for code conversionfrom ASCII to the hybrid code described below and formatting in the X.25transmission protocol to produce a packet and transmission to dataoutput 34 where it is forwarded to the lata switch 14 as indicated atpoint 312. Processing then proceeds to point 294 as described above. Ifthe answer was "no" at decision point 308 that the page is not destinedfor a lata switch 14 within the jurisdiction of the hub switch 16,processing proceeds to point 314 where the CPU 50 determines to whichhub switch 16 the page should be transmitted by use of the hub routingcodes 112 in the random access memory 48. The CPU 50 then determines thedestination hub switch 16 by matching the area destination of the pagewith a particular area destination within the hub routing codes 112 andcauses storage of the page in the corresponding outbound hub buffer 116which is the highest priority hub switch 16 to which pages are to besent in the matched hub routing code as indicated at point 316. The CPU50 of the hub switch 16 causes the page to be forwarded to the hubdestination upon the periodic reading out of the outbound hub buffer 16by transmission to the data module processor 32 for code conversion fromASCII to the hybrid code described below and formatting in the X.25transmission protocol to form a packet and forwarding to the data output34 where the page is transmitted to the hub destination as indicated atpoint 318.

Furthermore, it should be understood that programming of the pagingreceiver to receive pages in a new area(s) by updating the field 78 ofthe subscriber files may be accomplished by a local telephone call tothe local switch 12 having the subscriber file 54 containing thesubscriber identification code. The initiation of this programming isindicated by block 320. After verification of the secret code andmatching of the identification code transmitted with the page with anidentification code in the subscriber file 54 and reprogramming of thedestinations 78, processing proceeds to point 322 where the frequencyprogramming command is assembled. At point 324 the command afterbuffering and protocol formatting is transmitted to a transmitter 15 atthe local paging service as indicated and to the area codes (if any)specified in field 78.

It should further be understood that the updating of channel programmingcommand to be outputted to each of the areas stored in the field 78including those area(s) already present in the field and the newly addedarea(s). In this way, the highest probability exists for local pagingservice as indicated and to the area codes (if any) specified in field78.

It should further be understood that the updating of service by addingan area(s) to the field 78 causes the channel programming command to beoutputted to each of the areas stored in the field 78 including thosearea(s) already present in the field and the newly added area(s). Inthis way, the highest probability exists for the paging receiverreceiving the new frequency programming information.

XII. Local Switch Programming of Reception Frequencies in Response toPaging Traffic

FIG. 26 illustrates a block diagram of a system utilized by a localpaging service 18 having at least two transmission channels whichdynamically switches the channel on which paging receivers under thejurisdiction of the local paging service 18 are to receive pages fromone of the channels to another of the channels. As illustrated, the pairof local switches 12, which are identical to those described above withrespect to FIGS. 2 and 3, are connected to each other via thecommunication line 334 which preferably has a RS232 protocol. The localswitch #1 is connected to a local paging terminal 335 which representsthe part of a local paging service 18 which controls the transmitter 330transmitting pages on channel X. Similarly, the local switch #2 isconnected to a local paging terminal 336 which represents the part of alocal paging service 18 which controls the transmission of pages on atransmitter 332 on channel Y. It should be understood that typically thelocal paging terminals 335 and 336 are contained within a single localpaging service 18 but that in fact they are not limited thereto.Furthermore, the local switches #1 and #2 may be disposed in differentgeographical areas within broadcast range of the area served by thelocal paging service 18. It should also be understood that thetransmitters 330 and 332 may be located at a single transmissionfacility or may be disposed in separate locations within the servicearea of the local paging service 18. The local switches #1 and #2 may beimplemented in a high capacity switch having the functional capabilityof two individual local switches 12. Finally, the above-described systemmay be implemented with only two local switches and transmitters undertheir jurisdiction.

The system of FIG. 26 functions to change the paging receiver channel ofgroups of subscribers stored in a subscriber file 54 of one of at leasttwo local switches to the paging receiver channel of one of the other ofthe switches when traffic conditions on one of the switches reaches anoverload as described below. In the preferred form, the channel ofindividual subscribers is not changed but it should be understood thatthis could be accomplished in the alternative. Overload conditionstypically will happen during three peak traffic periods during a day butmay also occur randomly as dictated by service conditions. Theprogramming for implementing the operation of the local switches iscontained in the Microfiche Appendix referred to above. The local switchcontrolling the changing of the channel of a group of subscriber'spaging receiver to the channel of another local switch issues afrequency changing command discussed below to reprogram the channel ofeach of the paging receivers having a paging receiver identificationcode contained within the group of subscribers. The channel "X" oftransmitter 330 is utilized when the local switch #2 is overloaded withpaging traffic and the channel "Y" of transmitter 332 is utilized whenthe local switch #1 is overloaded with paging traffic assuming that bothswitches are not simultaneously busy. The local switch controlling thechanging of the channel of a group of paging receivers programs thedestination field 78 of the subscriber to forward pages within the groupof paging receivers to the port connected to line 334 of the otherswitch to cause each page to a paging receiver within the group to betransferred to the other switch by line 334 for transmission by itstransmitter. It should be understood that the compilation of the pageswhich are intended for paging receivers within the group of pagingreceivers that have their channel changed remains under the jurisdictionof the switch which initiated the change in the channel with only thetransmission of the pages being controlled by the other switch. Itshould be understood that this configuration in the network 10 replacesthe combination of the local switch 12, transmitter 15 and local pagingservice 18 associated with each lata switch 14 as illustrated in FIG. 1when the local paging service has two or more channels available. Itshould be understood that the number and the size of the buffers of thelocal switches are programmable by inputs from the keyboard 36.

FIG. 27 is a flowchart illustrating the operation of the system of FIG.26. It should be understood that the explanation of operation is equallyapplicable to either one of the local switches #1 or #2. Operationcommences at point 340 where the CPU 50 of one of the local switches 12determines the number of pages stored in its inbound data buffer 80 andinbound pages buffer 84. If the number is greater than a predeterminedprogrammable number, such as 70% of the overall capacity of pages whichmay be stored by these buffers, a condition exists in which it may bedesirable to shift the channel on which subscribers stored in thesubscriber file 54 of the one local switch are to receive pages from oneof the channels "X" and "Y" to the other of the channels "X" and "Y". Ifthe system does not have local paging terminals 335 and 336 which haveseparate subscriber files from the subscriber files 54 of the localswitches #1 and #2, then the determination may proceed directly todecision point 348 described below which eliminates the requirement fordetermining percentage of air time discussed below with reference tosteps 342, 344 and 346. If the number exceeds the aforementioned number,processing proceeds to point 342 where a determination is made of thepercentage of the air time over an immediately past time interval usedby the local switch in transmitting its pages with respect to the totalair time of the transmission of pages by the transmitter in transmittingpages from the associated local paging terminal and the local switch.This determination may be made for a period such as the five precedingminutes of operation. The assumption is that if the local switch 12 hasits inbound buffers substantially full, then the overall amount of timewhich it spent transmitting pages in the last five minutes will reflectits percentage of the overall air time. If there is no backup of pagesin the buffers 82 and 86 in the last five minutes of operation, there isassumed to be no backup of pages requiring frequency reprogramming ofchannel of the paging receivers. The CPU 50 determines the overall totaltime required to transmit the totality of the pages stored in each ofthe buffers 82 and 86 as indicated at point 344. At point 346, basedupon the overall percentage of transmission time which has been utilizedby the local switch during the predetermined time period, adetermination is made if the total required time to transmit thetotality of buffered pages contained in the buffers 82 and 86 does notexceed the available air time. In other words, if the local switchutilized 20% of broadcast time for an immediately past predeterminedtime of five minutes, then the total time required to transmit thenumber of pages stored in the buffers 82 and 86 must not exceed oneminute in order to avoid a backup. If the answer is "yes" at point 346,then the local switch proceeds as described above with reference to theoperation of the local switch to output the stored pages in the ID codebuffers 86 for transmission to its associated transmitter 330 or 332 asindicated at point 348. If the answer is "no" at point 346, theprocessing proceeds to point 349 where an inquiry is made to the otherlocal switch to determine if it has enough air time available totransmit the pages stored in its buffers 80 and 84. At this point itshould be noted that the control program of both local switches aresimultaneously making the determinations of steps 340-349. If the answeris "no" at point 349, which means that the other local switch 12 alsohas backlog pages, then the local switch does not issue any channelprogramming commands and maintains the current channel for all of thesubscribes in its subscriber files 54 as indicated at point 350. If theanswer is "yes" at point 349, operation proceeds to point 352 where theCPU 50 causes the generation of the channel programming command asdiscussed below to receive the page on the channel assigned to the otherlocal switch. Processing proceeds from point 352 to point 354 where apointer is placed in the field 78 to forward each page of the group ofsubscribers who have had their channel changed to the other switch. Itshould be noted that the formatting of a channel programming command istotally under the control of the switch initiating the changing of thechannel with the complete page being forwarded to the other switch underthe control of the aforementioned pointer.

At this point it should be understood that there are two main modes ofoperation which are the automatic and manual modes. During the automaticmode, the control program of the CPU 50 may be altered at the localswitch 12 by a suitable input such as from the keyboard and monitor 36prior to operation to shift the channel of a group of subscribers lessthan the total number of subscriber files or to shift the whole group ofsubscribers stored therein. During the automatic mode of operation, theshifting of reception frequency of a group of subscribers happenswithout human intervention. Shifting of the channel of the entiresubscriber file is an action which would normally be reserved for atransmitter failure or shutdown of the transmitter for maintenance. Whenless than all of the subscribers in the subscriber file 54 are to havetheir channel changed, the local switch may be programmed toautomatically identify those particular subscribers to have theirchannel changed to identify blocks of subscribers such as but notlimited to by the least significant digit of their identification code.The manual mode of operation is the same as described above except thatimplementation of the step at point 352 is performed with manualintervention which permits the choice of programming either all of thesubscribers which are resident in the subscriber file 54 as a group orsub-groups such as those having a common least significant digit intheir identification code 66.

XIII. International, National, Regional, Local, Sublocal and GroupPaging

As discussed above, the network 10 provides versatility in the level ofservice which may be provided to the subscriber. The subscriber mayelect international, national, regional, local, sublocal and grouppaging by use of the service option field 68.

A. Local Paging

When it is desired to program a paging receiver which is identified bythe pager identification code 66 of the subscriber file 54 to receivelocal service, the paging receiver is programmed to receive a fixedchannels either manually or automatically by use of the channelprogramming changing AC as described below. Automatic programming isaccomplished with the channel programming command AC discussed belowwith the desired channels being sent twice by identical channelprogramming command to the paging receiver by means of the transmitter15. The operating program of the processor of the paging receiverrecognizes the sequential sending of the same channel programmingcommand twice and stores the repeated channel in the area channelsection and operating channel section of the channel memory as discussedin detail in the above-referenced patent applications filed Oct. 20,1987. By storing only a single channel in its operation channel and itsarea channel sections discussed below, the paging receiver is forced toreceive only a single channel which is typically used for localoperation. It should also be understood that a paging receiver may beprogrammed to receive more than one channel

B. Sublocal Paging

FIG. 28 illustrates a block diagram of a system in accordance with thepresent invention for providing sublocal paging message services bymeans of pages transmitted from one or more sublocal paging systems orservices 368, 370, 372 and 374 through associated sublocal switches 360,362, 364 and 366 to the local switch 12 for broadcast by the transmitter15 of the local paging receiver 18 on a common carrier channel. Thechannel programming command, discussed below, is issued by the localswitch 12 to program the channel(s) of the paging receiver ofsubscribers resident in the subscriber file of the systems or services368-374 to the channel(s) of the local transmitter 15. A sublocal pagingsystem or service transmits pages to groups of subscribers maintained ina sublocal switch subscriber file 54 as described below to providespecialized services typically of the type not provided by a commoncarrier paging service such as the local paging service 18. A separatesublocal switch is provided for each of the sublocal services or systemsto be controlled. The circuitry of the sublocal switches 360, 362, 364and 366 is identical to the local switch described above with referenceto FIGS. 2 and 3 and they have the same general control program withnecessary modifications being made by input from the keyboard 36. Asillustrated, sublocal switches 360, 362, 364 and 366 are respectivelyassociated with a private municipal paging system 368, a privatehospital paging system 370, a stock quotation service 372 and any othertype of private service 374. Each of the sublocal switches and localswitch 12 has a telephone trunk(s) 375. A sublocal switch may be used inconjunction with any non-common carrier service or system with thenumber of sublocal switches not being limited to that as illustrated andfurther not being limited to any particular type of sublocal system orservice as illustrated. As illustrated, the private municipal pagingsystem 368 has a PABX or operator input 376, the private hospital pagingsystem has a PABX or operator input 378; the stock quote service 372 hasa link to a stock quote computer 380, and the other private service hasan input of any type of information 382 with it being understood thatthe inputs to the sublocal systems or services are of any nature tosupport the function performed by these systems or services. Thefunction of these systems is to permit specialized forms of informationto be broadcast in the form of a page to subscribers of the services orsystem 368, 370, 372 and 374 either by means of their associatedsublocal non-common carrier transmitter 384, 386, 388 and 390 or bymeans of the local switch controlling the transmitter 15 of the commoncarrier of the local paging service 18. Each of the sublocal switches360, 362, 364 and 366 are connected to the local switch by means of acommunication link 384 which may be a telephone trunk.

Each of the sublocal switches 360, 362, 364 and 366 has a memory map asillustrated in FIG. 3 with a private service option field 68 (notillustrated) being utilized to permit election of sublocal service whichutilizes only the transmitter 384, 386, 388 or 390 associated with thesublocal switches 360, 362, 364 or 366 or local, regional, national orinternational service provided by the network 10. The channelprogramming command AC is issued to program the channel of the pagingreceiver of the subscribers within the subscriber file 54 of the localswitch 18 to receive a page originating from the sublocal switchbroadcast by the local transmitter 15. The other service options remainwhich permit a subscriber to the systems or services 360, 370, 372 or 74to elect the other service levels provided by the network 10. When thesubscriber to the private systems or services elects to utilize thetransmitter 15 of the local paging service 18, the subscriber calls thelocal switch 12 and enters the four-digit secret code to obtain accessto the subscriber files 54. The subscriber then requests service otherthan sublocal transmission by the transmitters associated with thesystems or services 368, 370, 372 and 374 by specifying a service optionof either local service which corresponds to the local service describedabove with reference to field 68 of the local switch memory map of FIG.3 or some other wider level of broadcast service by entering the serviceoption and the area code(s) of the destinations. The destination code406 discussed below with reference to FIG. 30 is transmitted with thechannel programming command which is stored by the paging receiver. Allpages which originate from a sublocal switch that are broadcast by thetransmitter 15 are broadcast with the destination code 406 as the firstcharacter of the identification code to save battery power of the pagingreceiver. The local switch 12 programs the channel(s) to be received bythe paging receiver to those used by the service areas of thedestination field 78 of the subscriber file by transmission of thechannel programming command by the transmitter 15 and to the network 10if a level of service greater than local service is requested. Theregional and national service options also utilize the destination code406 as described below. The sublocal switch receives each page from theassociated system or service and formats the page with the appropriateidentification code including destination code 406 and system command asdescribed below including the hybrid code described below and adding ofthe X.25 transmission protocol to form a packet. The sublocal switchthen forwards the packet to the local switch 12 for processing anddistribution to the destinations specified by the destination field 78in accordance with the function of a local switch 12 as described abovewith reference to FIGS. 2 and 3. When the local switch 12 receives apage from one of the sublocal switches via communication link 384, itcompares the identification code of the page with the subscriber file 54to find a match and determines the destination(s). For a local serviceoption the page is processed as a page received from a lata switch 14,and broadcast by the transmitter 15. If regional, national orinternational service has been elected then the local switch 12 forwardsthe page(s) to system 10 for processing as described above. If thesubscriber wishes to return to the status of only receiving pages viatransmission of the sublocal switches and private transmitter, then acall is made to the sublocal and local switches to reprogram the serviceoptions in field 68 to specify only private service over which theswitch 12 does not have jurisdiction.

C. International, National. Regional and Group Paging

International, national and regional service are provided by thetransmission of packets of pages between switches in the network 10. Thechannel programming command AC is used to program the paging receiver ofthe subscriber to receive the channels for the areas identified in field78 which are stored in the frequency file 56 which are associated withthe designated areas. Thus, if regional service is elected for area code312 or national service is elected to cover a plurality of area codessuch as 312, 202 and 212, the local switch 12 issues a channelprogramming command AC discussed below which is broadcast to all of thespecified area codes as well as the broadcast area of the transmitter 15with channels chosen from the frequency file.

Group paging is analogous to sublocal paging except that the pages aredirected to a selected group of paging receivers within the jurisdictionof the local switch 12. The destination code 406 which is discussedbelow in detail is added as the first digit of the paging receiveridentification code to limit the sampling time required by the localpaging receiver to determine if the page is intended to be received byit as part of the group.

D. Limiting of Battery Consumption of Paging Receivers for Sublocal,Group, Regional, National and International Paging

FIG. 29 illustrates the order of transmission of digits of theidentification code for all pages which are broadcast by a local pagingservice 18 for subscribers stored within its subscriber identificationfiles 54. Each circled number indicates the significance of the digit ofthe identification code with the most significant digit being identifiedby the largest number. The area designation field 402 is the countrycode and area code of the geographical location where the local switch12 is located With the most significant digit being the country codefollowed by the next three most significant digits which comprise thearea code. For example a local switch in the Chicago area would have afield 402 of "1312". The field 404 are the digits which identify thesubscribers of the local switch. The arrow pointing to the leftillustrates the order of transmission of the digits of theidentification code with the least significant digit being transmittedfirst sequentially followed by digits of increasing significance withthe most significant digit being transmitted last. This order oftransmission produces a substantial increase in battery life of thepaging receiver because the individual paging receiver samples fewerdigits of the identification code on any given channel to determine if apage on that channel is addressed to a particular paging receiver thanif the digits are transmitted in an order of decreasing significance asin the prior art.

FIG. 30 illustrates the use of the destination code 406 to limit powerconsumption in paging receivers for sublocal, group, regional, nationaland international paging. Identical reference numerals identify likeparts in FIGS. 29 and 30. The only difference between local paging onone hand and sublocal, group, regional, national and internationalpaging on the other hand is that a destination code 406 is added to theidentification code of pages as the least significant digit which aretransmitted to paging receivers which are to receive group, sublocal,regional, national or international service pursuant to the serviceoption field 68 discussed above. The destination code 406 has one ormore characters which precede the paging receiver identification codethat are not matched by a paging receiver which is to receive only alocal service page. This ensures that only paging receivers which areprogrammed to receive international, national, regional, sublocal andgroup pages may be turned on to sample more than one digit of theidentification code of pages intended for international, national,regional, sublocal and group service options when transmission occurs ona local frequency. Paging receivers which are programmed for theinternational, national, regional, sublocal and group service optionswill only turn on for one digit of local service options on a channelbefore a mismatch occurs that causes the paging receiver to turn off forpages broadcast local pages. In a preferred form of the invention, thedestination code 406 is a letter, which is transmitted prior to thetransmission of the paging receiver identification code. Since localpages do not transmit any letters with the identification code, amismatch will occur immediately for paging receivers programmed toreceive nonlocal service pages. Paging receivers which are to receiveinternational, national, regional, sublocal or group pages areprogrammed by the channel programming command AC to store a destinationcode as a header on the channels broadcast with the channel programmingcommand. Thus, on a particular channel where some pages are transmittedwith destination codes, only the first digit of each page is required tobe compared with any stored destination code to enable an identificationby a paging receiver programmed to receive pages with destination codesif a page is potentially directed to that paging receiver. The pagingreceiver which has been programmed with a destination code immediatelyturns off when a match is not found between the first digit of a page ona received channel and the stored destination code which occurs forpages broadcast as part of local service thereby saving power requiredto compare the following digits of the stored and transmitted pagingreceiver identification.

When it is desired to program a paging receiver to receive pages to usethe destination code 406, the individual channels of the area channelsection of the channel memory, as discussed below, of the pagingreceiver as discussed in detail in the above-referenced applicationsfiled on Oct. 20, 1987 are programmed by the channel programming commandAC as described below. The first digit of the channel frequencies whichare to be programmed to be received by the channel programming commandAC contain the destination code 406 character such as the letter A, B,C, etc., which is not recognized as part of a paging receiveridentification code for only local paging, which preferably are base tennumbers. Thus, paging receivers which are programmed for local pagingservice on a channel also being used for international, national,regional, sublocal or group paging will immediately detect a mismatchwhen the first digit of a page intended from national, regional,sublocal or group service is received which saves battery life. When apaging receiver which has been programmed for international, national,regional, sublocal or group service receives the first digit of thepaging receiver identification code, that digit is compared with thefirst digit of the channels stored in the area channel section of thepaging receiver channel memory. If a match occurs, the operating programof the paging receiver causes the RF tuner to stay in an "on" state tocompare the subsequent digits of the received identification code withthe stored paging receiver identification code stored by the pagingreceiver until a mismatch or a complete match is found. If there is nomatch between the first digit of the transmitted page and thedestination code, then the paging receiver RF tuner is immediatelyturned off to save battery power.

XIV. X.25 Transmission Protocol

FIG. 31 illustrates a preferred transmission protocol to be used fortransmitting packets of pages between switches. The protocol which isused is a modified X.25 protocol. As illustrated, each packet containsfive separate layers. The first layer is the destination telephonenumber which is the receiving port to receive the page. With referenceto FIG. 1 if a packet of X.25 formatted pages were to be sent from afirst lata switch 14 to its associated hub switch 16 over communicationpath 20, the destination telephone number would be the telephone numberof the hub switch. It should be further understood that the X.25transmission protocol as described herein may be utilized with othertypes of communication mediums between switches such that a destinationtelephone number may be replaced with another form of address of thereceiving switch. The second layer indicates the packet size field interms of succeeding layers of information. In the present case levels 3,4 and 5 are provided which dictates that the packet size would store thenumber 3 to indicate the subsequently lower third, fourth and fifthlayers. The third layer contains an origination switch address and adestination switch address which can be either telephone numbers or realaddresses within the network 10. The fourth layer is the number of pageswhich are contained in a packet. As illustrated, this number may be anyinteger n. The fifth layer is one or more pages which each correspond toan individual page to be sent to a particular paging receiver.

Each message includes the following information. In accordance withstandard X.25 protocol, a beginning of file header is included.Following the beginning of file header is a pager I.D. code which is theidentification code of the destination paging receiver which isidentical to the subscriber identification code stored in the subscriberfiles 54 of the subscriber to receive the page. Following the pager I.D.code is the destination(s) of the page which is geographicallydescriptive of the area to which the page is to be transmitted and isadded by the local switch 12 interrogating the destination field 78 ofFIG. 3. In the preferred embodiment, the destination is a combination ofcountry and area code as utilized by the telephone system to identifythe area to which the page is destined. For each country, the samecountry code will be used so that if the paging system 10 as illustratedin FIG. 1 were to be utilized for the United States, the first digit ofthe destination would be a 1. Similarly, the destinations in othercountries would be followed by different numbers identifying thosecountries followed by code which breaks up the identified country intosmaller geographic regions. While the utilization of area codes underthe telephone system facilitates the usage of the present invention, itshould be understood that a destination which is not based on thetelephone system is equally usable with the present invention. The fieldof special commands are the system commands described below which aretransmitted with each page to a paging receiver. The "page" is the partof the page which is to be displayed to the bearer of the pagingreceiver and may be numeric or alphanumeric characters. The end of thefile and file size information are part of a standard X.25 protocol.

XV. Hybrid Page Code

In a preferred form of the present invention a hybrid code is utilizedwhich is compatible with both analog and digital FM paging transmittersnow currently in use. Preferably, this code is used for coding all formsof transmissions in the system. This hybrid code uses sequential tonesto encode numerical pages transmitted with the A3, C3, A5 and C5commands discussed below. This hybrid code utilizes two sequential tonesto encode each numerical or alphanumerical character of alphanumericpages transmitted with the A4, C4, A6 and C6 commands discussed below.Each tone represents one of 16 possible values in a hexadecimalnumbering system as follows: 600 Hz.=0; 741 Hz.=1; 882 Hz.=2; 1023Hz.=3; 1164 Hz.=4; 1305 Hz.=5; 1446 Hz.=6; 1587 Hz.=7; 1728 Hz.=8; 1869Hz.=9; 2151 Hz.=A; 2435 Hz.=B; 2010 Hz.=C; 2295 Hz.=D; 4059 Hz.=E; andno tone (absence of modulated carrier signal)=F. The processing by theindividual paging receiver of the above-described hybrid code isdiscussed in detail in the above-referenced patent applications filed onOct. 20, 1987. Thus, it should be understood that the "page" field ofthe X.25 packet described above with respect to FIG. 31 is transmittedwith one tone being used to encode each number of a numerical page andtwo tones being used to code each alphanumeric or numeric digit of analphanumeric page. The encoding format utilized for digits of thealphanumeric commands in the preferred embodiment is set forthbelow.______________________________________CONVERSION TABLESuccessiveSuccessiveValues Character ValuesCharacter______________________________________01 ! 51 S02 " 52 T03 # 53U04 $ 54 V05 % 55 W06 & 56 X07 ' 57 Y08 ( 58 Z09 ) 59 [10 * 6011 + 61]12 ' 6213 - 63 ≈14 . 6415 / 65 a16 0 66 b17 1 67 c18 2 68 d19 3 69 e204 70 f21 5 71 g22 6 72 h23 7 73 i24 8 74 j25 9 75 k26 : 76 l27 ; 77 m28< 78 n29 = 79 o30 > 80 p31 ? 81 q32 82 r33 A 83 s34 B 84 t35 C 85 u36 D86 v37 E 87 w38 F 88 x39 G 89 y40 H 90 z41 I 91 {42 J 92 |43 K 93 }44 L94 →45 M 95 ←46 N 9647 O 9748 P 9849 Q 9950R______________________________________

It should be further understood that display of the characters set forthabove in the English language is controlled by the first letter of theinput commands used for making alphanumeric or numeric pages asdescribed above. Although not illustrated, corresponding Kanjicharacters of the Japanese language are transmitted by using the sametwo digit address and varying the first character of the commandsdescribed below from the letter "A" for English display as discussedabove to the letter "C" for display of the corresponding Japanesecharacter. Thus, with respect to the conversion table set forth above, acommand as described below requesting alphanumeric display of anexclamation point in English would be encoded with the sequence "01"with the command beginning with the letter "A" and the display of thecorresponding character in Kanji format would also be encoded by thecombination of digits "01"with the command beginning with a "C". Everycommand which is to be executed in conjunction with a page in Englishbegins with a "A" and every command which is to be executed inconjunction with a page in Japanese begins with a "C".

Pages which are to be transmitted to an external device through thepaging receiver have the "page" field described above coded in thehybrid code at a 1200 baud rate. For the X.25 transmission of pages toan external data device each bit is encoded in 833 microseconds and eachbit in all other transmissions of pages which are coded in the two-toneencoding format described above is coded with 8.2 milliseconds.

XVI. Commands The command repertoire of the present invention permitsthe functionality of the paging receiver to be changed dynamically bythe network 10 in a manner not achieved by the prior art. All commandswhich are executed by the paging receiver are sent according to acommand protocol. An example of the command protocol is set forth belowwith a nationwide telephone number page to paging receiver ID 789 12345with telephone number 424, 6464 and a warbletone.______________________________________ FF - - 5 - - B4 BE 321 BE987 A7 424 DE 6464 AEANOTES11A22345______________________________________FF Provides 66 m.s. ofsilence prior to the page.NOTE 1 Is the least significant digit of thepaging receiver identification code which is sent first as the preamble.If the page is a group page, a C may be substituted for the 5.NOTE 1AWhen a "B" appears after the preamable digit, the person receiving thepage will be alerted that a "batched" page is occurring to be sent to agroup of paging receivers. Batched pages are outputted from the buffers86.NOTE 2 The BE's are received by the paging receiver and ignored andprovided time spacing.NOTE 3 A7. The A signifies that a command sequencefollows. The 7 indicates the message is numeric, and illuminates anationwide origin display in the paging receiver and telephonemessages.NOTE 4 DE's are sent during the data character portion of thetransmission to allow overlay operation.NOTE 5 AEA or AE indicates theend of transmission and the type of alert tone to use e.g.warble.______________________________________

The command protocol also permits the repeating of digits, the placingof group calls and batches of pages to be sent from identification codebuffers 86 as explained below.

The repeating of digits 799 12225 is as follows:

FF--5--2 BE2E1 BE987

The command protocol will never allow the same two numbers to besuccessively sent. An E is substituted for the second number or letter.i.e.

12225=12E25

44BB5=4EBE5

38111=381E1

11111=1E1E1

Group calls to groups of paging receivers are explained as follows:

The "C" tone is substituted for a digit for group calls. Groups are10,100,1000, etc. orall.______________________________________i.e.______________________________________78912345 (no group call)789 1234C (10 pagers) (0-9)789 123C5 (10 pagers)(05,15,25 etc.)789 123CC (100 pagers) (00-99)789 CCCCC (100,000pagers)CCC CCCCC (all pagers)______________________________________

The transmission of batched pages occurs from the identification codebuffers 86 within the example below the page being 789-12345. If a "B"tone immediately follows a preamble tone, all paging receivers with the5 preamble in their identification code will remain on to search fortheir identification code. Batching of pages allows one preamble to besent, and then multiple pages to follow within the same preamble group.The following pages will then be sent with the preamble digit 5eliminated. Each paging receiver will remain on, searching for the AE orAEA end of page combination. If a page does not follow within 300 m.s.,the paging receiver will return to sample mode. If a page follows with anew preamble digit of 1900 m.s. duration, the paging receiver will alsoreturn to sample mode.

FF--5--B4BE321BE987A7 (ETC.)

Three batched pages are as follows:

987-12345, 987-12435, 987-12125

FF2BE121BE789A4

FFB3BE421BE789A3AEA

FF2BE121BE789A4

Note that "B" is sent on following pages, and the "5"is eliminated onfollowing pages (the 5 is not necessary on following pages as the firstpage sends 5B which alerts all "5"paging receivers that batcing isoccurring). The last page of the batch will not have a "B" sent to allowthe paging receivers to digit mismatch and return to sample mode. Itshould be noted that each of the local switches has the capability ofbatching pages into a single page having a plurality of identificationcodes contained in each page.

The operating program of the main CPU 50 of the switch is programmed togenerate commands which are transmitted with each page which aredictated by the operation of the system and the specified serviceoptions in field 68. As explained above with reference to FIG. 31, acommand sequence follows the paging receiver identification code anddestinations. The command sequence begins with an "A" character followedby a command character for English language pages and with a "C"character followed by a command character for Japanese language pages.Set forth below is a command table explaining the command structure.While the English language commands are the only commands discussed inthe examples below, it should be understood that the Japanese languagecommands are identical in function and are illustrated in thetable.______________________________________COMMAND TABLEEnglishJapanese______________________________________A0 C0 BATTERY SAVEA1 C1REPEATA2 C2 PROGRAM IDA3 C3 LOCAL & NUMERIC (16 NUMBERS)A4 C4 LOCAL &MESSAGE - ALPHA (511 CHAR)A5 C5 NATIONAL & NUMERIC (16 NUMBERS)A6 C6NATIONAL & MESSAGE-ALPHA (511 CHAR.)A7 C7 ALPHA FIXED MEMORY LOCATIONA8C8 RESERVEDA9 C9 EXT DATA (OPENS AUDIO TO EXIT JACK)AA CA DO NOT USE!ABCB OUT OF SERVICEAC CC CHANNEL PROGRAMAD CD COMPANY MESSAGEAE CE DO NOTUSE!______________________________________

The A1, A3-A7, A9 and AD commands are automatically generated by CPU 50of local switch 12 as a function of the service options in field 68 ofthe subscriber files 54. In other words, the programming of field 68automatically dictates the command structure to be used. Furthermore,the AC command is utilized by the system for programming the channelfrequency of the paging receivers as described above in sections XI, XIIand XIII as well as any time the system is used to reprogram thechannels to be received by the paging receiver. A number in parenthesisidentifies a part identified within the drawings of the above-referencedpatent applications filed on Oct. 21, 1987.

A0 and C0 Battery Save

The battery save command is followed by a two digit decimal formatindicating how many seconds the paging receiver should be turned offbefore beginning its channel sampling. It is followed by an AE messageterminator with no tone alert necessary. The two digit number representsthe number of 10 second increments the paging receiver should be turnedoff with a maximum of 990 seconds (16.5 minutes).

A022AE=220 second turned off period

A099AE=990 second turned off period

A1 and C1 Repeat Page

The repeat command indicates that the page being sent is a repeat of theprevious page. The previous message display will be used, and thenumeric character or alphanumeric character page should match a previouspage which has been stored in the random access memory (60) of thepaging receiver during the execution of the A3-A6 commands which cause apage to be stored in the random access memory. If a page match isdetected by the paging receiver, the page is discarded. If the firstpage was not received, the page should be stored in the random accessmemory (60) of the paging receiver and the wearer of the paging receiveralerted. The display (64) will show "RPT" indicating a repeat page andthe first page was not found in memory, i.e.,

A1, A3 424DE6464AE REPEAT 424-6464 (local, numeric, which is theexecution of command A3 described below)

A2 and C2 Program ID

The program ID command is used to send a new paging receiveridentification code 66 to the paging receiver. The previous pagingreceiver identification code will be overwritten by this command. Notone alert is necessary, but the paging receiver should display the newpaging receiver identification code as a page, i.e.,

CHANGE 789 1234 TO ID 789 45678 A2789DE4567DE8AE (NEW ID)

A3 and C3 Local Numeric (16 Digits)

The A3 command sequentially illuminates the display (64) of the pagingreceiver described in the above-referenced patent applications filed onOct. 21, 1987, indicating the page is of local origin, and a numericcharacter display (telephone number) as a page. This command is used totransmit pages originating within the jurisdiction of the local switch12 which controls the transmitter 15 broadcasting the page. The numericcharacters are sent as sequential tones. The paging receiver and decodeindividual characters will receive the page as single digits, i.e.,

A3956DE1030AE TEL#956-1030

The maximum numeric length is 16 digits.

A4 and C4 Local Message alphanumeric (511 characters)

The A4 command sequentially illuminates the display (64) of the pagingreceiver of the above-referenced patent applications filed on Oct. 21,1987 indicating the page is of local origin and an alphanumeric displayas a page. The alphanumeric format is sent with each character beingencoded as a two digit number as explained above. The paging receiverwill receive and decode individual characters of the page as sequentialtones. The message length will be 511 characters or less. This commandis used to transmit pages originating within the jurisdiction of thelocal switch 12 which controls the transmitter 15 broadcasting the page.The display (64) will flash, indicating the message is 511 characterslong,i.e.,__________________________________________________________________________IBMSTOCK $124 3/4(18 CHARACTER MESSAGE)A4 41 34 DE 45 32 DE 51 52 DE 47 35DE 43 32 DE 04 17 DE18 20 DE 32 19 DE 15 20 AE (56 CHARACTER 1.848SEC.)__________________________________________________________________________

The A5 command sequentially illuminates the display (64) of the pagingreceiver described in the above-referenced patent applications filed onOct. 21, 1987 indicating that the origin of the page is not within thejurisdiction of the local switch 12 controlling the transmitter 15broadcasting the page and a numeric character message as a page. Thiscommand is used by a local switch 12 for relaying a page through thenetwork 10 to a transmitter 15 located at a remote area (an area otherthan where the subscriber file is located) where a paging receiver is toreceive a page transmitted by the transmitter located at the remote areasuch as between local switch #1 of lata switch #1 to local switch #1 oflocal switch #m of FIG. 1. The numeric characters are sent as sequentialtones. The paging receiver will receive and decode characters of thepage in a single digit format,e.g.,______________________________________TEL # 956 1001A6956DE10E1AE(NOTE: REPEAT DIGIT FOR SECONDZERO)______________________________________

A6 and C6 National Message (511 Char.)

The A6 command sequentially illuminates the display (64) of the pagingreceiver described in the above-reference patent applications filed onOct. 21, 1987 indicating that the origin of the page is not within thejurisdiction of the local switch 12 controlling the transmitter 15broadcasting the page an alphanumeric message as a page. This command isused by a local switch 12, for relaying a page through the network 10 toa transmitter 15 located at a remote area (an area other than where thesubscriber file is located) where a paging receiver is to receive a pagetransmitted by the transmitter 15 located at the remote area such asbetween local switch #1 of lata switch #1 to local switch #1 of localswitch #m of FIG. 1.

The maximum message length is 511 characters. The example is identicalto the A4 command discussed above with the first two characters beingA6.

A7 and C7 Alphanumeric Specific Message Memory

The A7 command permits a subset of commands to follow. The digitimmediately following the A7 command will indicate in which section ofaddressable sections of the random access memory (60) of the pagingreceiver described in the above-referenced patent applications filed onOct. 21, 1987 the page is to be stored. If a page exists in this memorylocation of the random access memory, it will automatically overwritethe page stored therein. The command subset will be 1-4 indicatingmemory locations (11-14) of the random access memory (60). An ordinarypage will not overwrite the (11-14) page locations. The page willimmediately follow:

A7 1 (page location 11)

A7 2 (page location 12)

A7 3 (page location 13)

A7 4 (page location 14)

The page locations (11-14) will only be overwritten by pages with thesame command (e.g. memory location 11 will only be overwritten by the A7(1) command) or erased by the user. The page type will always be"Special Call" and will be sent as an alphanumeric page.

A8 and C8 Reserved A9 and C9 External Data Message

The A9 command alerts the person being paged that the audio must berouted to the external data jack (67) of the paging receiver describedin the above-referenced patent applications filed on Oct. 21, 1987 forremote processing. The paging receiver will forward the audio to theexternal data jack (67) until the AE message is received, indicating endof data transmission, i.e. A9--DATA--AE.

The A9 command plays an important part of the present invention'sfunctionality in offering diverse data services by permitting theconnection of peripheral devices to the paging receiver. Thus, diversedata services such as but not limited to telex and facsimile may beoffered with the paging receiver acting as the receiver which forwardsreceived data to a peripheral device.

AA and CC Invalid

The AA command cannot be used, as it would be processed by the main CPU(24) as an AE (end of file) command.

AB and CB Out of Service

The AB command will illuminate an out of service display on the display(64) of the paging receiver described in the above-referenced patentapplications filed on Oct. 20, 1987 and may or may not have numeric datafollowing. This command may be used when system maintenance is required,or to alert the wearer of the paging service that service is beingdenied, until the bill is paid, i.e. ABAE (illuminates out of servicemessage upon turn on and for two seconds).

The paging receiver still receives messages as normal. An out of rangedisplay turns on. The display (64) displays "out of service" until thenext page is allowed. The network 10 will prevent any messages frombeing sent to the pager.

AC Channel Programming

The AC channel programming command is one of the most important commandsin the system in providing paging services. The AC channel programmingcommand alerts the person wearing the paging receiver that channelfrequency programming information is forthcoming. The channelprogramming command is not transmitted with characters comprising a pageto be displayed or outputted by a paging receiver an only includesinformation for changing at least one channel of a paging receiver towhich the channel programming command is addressed. The channels arestored in the channel memory (62) of the paging receiver, described inthe above-referenced patent applications filed on Oct. 20, 1987 whichare transmitted as four digit decimals numbers, each separated by the DEdelimiter. As explained in the patent applications filed on Oct. 20,1987, up to 15 channels may be loaded into the area channel section orthe operation channel section. A preceding V indicates VHF, a U UHF, a Jindicates Japan and an E indicates Europe.

When only one channel is desired, such as for local paging, the channelis repeated at least twice, to alert the paging receiver that only onechannel is desired to be programmed in the area channel section of thechannel memory (62). All previous channels in the area channel section(66) of the channel memory 62 are erased. The memory cells have the newchannel number entered to fix the paging receiver to receive a singlechannel. The memory cells will remain programmed until the next channelreprogramming of the paging receiver, i.e.

AC0123DE0123AE (CH.V 123 NO SCANNING)

AC0E10DE0107DE0210DE1050DE7AEA (CH.v10,v107,u210,u50).

The channel programming sequence is as follows:

0001-0DDD VHF 5 KHz steps

1001-1DDD VHF 6.25 KHz steps (Europe)

2001-2DDD UHF 5 KHz steps

3001-3B2B 280 MHz 2.5 KHz steps (Japan).

Channel codes 4001, 5001, 6001, 7001, 8001, 9001 are open for additionalchannels to be added. The total upward reserve channel capacity in ROM58 is 16,458 channels.

The following sub-commands are utilized for instructing the main CPU toperform functions pertaining to the programming of channels.

NO Command (Add One Channel)

When no sub-command is sent, one channel is to be added to the areachannel section (66), e.g. AC 0237 DE 7AEA (add VHF channel 237 to areachannel section).

Sub-command 4000 (Typically Regional)

When 4000 is transmitted, it erases the entire area channel section (66)and the operation channel section (64) of the channel memory (62) andcannot be used in adjacent areas which must be programmed with the 6000sub-command. e.g. AC 4000 DE 0156 DE 2132 DE 7AEA. This command erasesand stores VHF 156 and UHF 132 channels frequencies in the area channelsection (66).

Sub-command 5000

When 5000 is transmitted, the destination code may be programmed. Thiscommand erases the operating channel section (64) and the area channelsection (66) and forces the reception of a particular channel. Thecommand is used for dynamic frequency agility. The paging receiver isfixed to receive a fixed channel. e.g. AC 5000 DE 0171 DE 7AEA. Thiscommand erases the operating channel section (64) and the area channelsection (66) and forces the paging receiver to VHF channels 171, causingthe operating channels section to store VHF channel 171.

Sub-command 6000 (National)

This command is divided into the loading of the 15 possible destinationcodes (96) and the channels.

ACB6122 DE0200 DE0000 DE0000 DE0000 DE02l2 DE0311

DE0408 DE2511 DE2139 DE7AEA

This represents the 6000 national command followed by the destinationcode (96) or local code for each of the 15 possible channels in the areachannel section. The five channels follow and will be as follows:

6122 National, channel 1=A, channel 2=B, channel 3=B

0200 Channel 4=local, channel 5=B, filler code

0000 Channel 8=11, filler code

0000 Channel 12-15, filler code

0212 VHF channel 212

0311 VHF channel 311

0408 VHF channel 408

2511 UHF channel 511

2139 UHF channel 139

7AEA Stop channel command.

Channel Programming Termination (7AEA)

The channels to be sent to the paging receiver are sent in the followingorder:

0XXX channels (VHF) (ascending numerical order)

1XXX channels (VHF Europe)

2XXX channels (UHF Europe)

3XXX channels (280 MHz).

The last channel sent is actually a terminate message code. It is 7AEA(7AAA).

The paging receiver will receive the last frequency code and immediatelyterminates the page. The 7AEA terminate frequency code is necessary atthe end of every AC channel program message. During the transmission ofchannel codes, the AEA code may appear (e.g. channel 1AEA). In order toprevent termination of the message, the AC command changes the AEAtermination command to 7AEA. 7AEA is an invalid channel code.

AD and CD Company COMMAND

The AD command allows a 32 alphanumeric character company message to besent to the paging receiver. The message is always alphanumeric, e.g.,AD 4247, DE 4637, DE 5100, DE 4833, DE 3941, DE 4639, AE Jones Paging.

When a company message is desired, it will be sent after the pagingreceiver identification code has been programmed. When the pagingreceiver is turned on, the company message will be displayed instead ofa self test message which is typically used. If no company messageresides in the paging receiver, the self test message will display.

The 32 character part of the random access memory (60) is batteryprotected to permit the message to permanently reside in the pagingreceiver. It may be changed by simply sending a new AD command andmessage to the pager. This permits the company message to be changed atwill.

AE and CE--Invalid

The AE command cannot be used, as it cannot be encoded and alsoconflicts with the end of file command.

End Of Page Command AE and CE or AEA and CEA All pages require the endof page command. The end of page command serves a two fold purposeindicating the end of transmission and determines the type of tonealert.

AE=2041 hertz--50% duty cycle--2 seconds

AEA=2041 hertz--25/75% duty cycle--2 seconds

Certain commands do not send a tone alert. A listing of the commands isas follows:______________________________________A0 BATTERY SAVE (NOALERT)A1 REPEAT (NO ALERT)*A2 PROGRAM ID (ALERT) - DISPLAY IDA3 LOCAL &TEL NUMERIC (ALERT)A4 LOCAL & ALPHA (ALERT)A5 NAT. & TEL NUMERIC(ALERT)A6 NAT. & ALPHA (ALERT)A7 ALPHA FIXED MEMORY (ALERT)A8 UNASSIGNED(ALERT)A9 SPECIAL & DATA AUDIO (ALERT)AB OUT OF SERVICE (ALERT)ACCHANNEL PROGRAM (ALERT)AD COMPANY MESSAGE(ALERT).______________________________________ *Al will alert if firstpage was not received or if previously erased.

While the invention has been described in terms of its preferredembodiments, it should be understood that numerous modifications may bemade thereto without departing from the spirit and scope of theinvention as defined in the appended claims. The network 10 is notlimited to the commands, code used for coding characters of the pagesand transmission protocol described above with reference to thepreferred embodiment. Furthermore, while in the preferred embodiment,the code used for coding characters of pages transmitted betweenswitches is different than the code used by the RAM 48 and CPU 50, itshould be understood that the invention may be practiced without usingany code conversion including the code conversion performed by the datainput 30, data module processor 32 and data output 34. While thepreferred form of the switches utilizes a PC and hardware assist toperform necessary processing operations, it should be understood thatthis configuration of processing is not required with other processingconfigurations utilizing hardware and/or software to perform thedislcosed functions of the switches being within the scope of theinvention. While the preferred form of transmitting pages between theswitches utilizes grouping of the pages to be transmitted betweenswitches into one or more packets which each have a switch as areadestination, it should be understood that the invention is not limitedto utilizing of packets. While the preferred form of the inventionutilizes the memory maps of FIGS. 3, 5 and 7, it should be understoodthat other storage configurations of memory may be used in accordancewith known memory storage techniques including those which do notspecifically allocate individual storage areas for storing a single typeof data such as the preferred memory maps. While in the preferred formof the invention, the pages are transmitted as packets with atransmission protocol, it should be understood that the pages may besent individually or in groups, without a transmission protocol, to asingle receiving switch and processed by the receiving switch inaccordance with the area destination of the individual pages andtransmitted to an output for further transmission without formattinginto packets. It should be understood that the cost of transmittingpages in the network is substantially lowered by the function of theswitch in originating a page and the switches located in the networkbefore a final area destination switch of a page in formulating groupsof pages for transmission to a single switch area destination fortransmission between switches. Finally, it should be understood that theterminology "identification code" and "identification number" and "code"each describe the combination of one or more characters includingletters or numbers with the terms being used interchangeably throughoutthe specification to identify information processed by the switches.

We claim:
 1. A paging network permitting requests for placing pages tobe made throughout the network providing service in a plurality ofgeographic areas without the placing of a long distance telephone call,each request for placing a page including an identification number of asubscriber to be billed for the page and a paging receiver to receivethe page with specified digits of the identification number identifyingan area within the paging network where a subscriber file storinginformation pertaining to the subscriber including any areas in thenetwork where pages are to be transmitted in the network which are to becharged to the subscriber's account and a subscriber identificationnumber is stored comprising:(a) a plurality of lata switching means,each lata switching means being located in a geographic region servicedby a separate telephone area code and including a telephone port forreceiving telephone calls requesting a page to be placed from within thearea code without a long distance telephone call to be transmitted bythe network to a switching means within the network; (b) a plurality oflocal switching means, each local switching means being under thejurisdiction of a single lata switching means and coupled to a localpaging service which broadcasts paging and each lata switching meanshaving at least one local switching means under the jurisdiction of thelata switching means; (c) means, coupling the lata switching meanstogether in the network, for transmitting requests for placing a pageand pages between lata switching means; (d) each lata switching meansprocessing the specified digits of the identification number of requestsfor placing a page received by a non-long distance call to the lataswitching means and from means coupling the lata switching meanstogether in the network to determine if the specified digits of therequest for placing a page match digits identifying the lata switchingmeans and transmitting those requests for placing a page which havespecified digits that identify the lata switching means to a localswitching means under jurisdiction of the lata switching means whichstores a subscriber file containing an identification number matchingthe identification number accompanying the request for placing a pageand transmitting all other requests for placing a page to the means fortransmitting requests for transmission to another lata switching means;(e) the means for transmitting the requests transmitting the requestsfor placing a page to a lata switching means which is identified withthe specified digits of the identification number; and (f) the localswitching means, having a subscriber file containing an identificationnumber of a subscriber matching the identification number contained inthe request to place a page, interrogating the subscriber filecontaining the matched identification number and forming at least onepage with each page having the local paging service as a destination ora switching means as an area destination in the network agreeing with anarea destination in the network stored in the subscriber file containingthe matched identification number when pages for the matched subscriberare to be transmitted in the network.
 2. A paging network in accordancewith claim 1 wherein:the subscriber file of each subscriber is stored bya single local switching means with all formulation of switching meansas area destinations in the network of pages being performed by thelocal switching means storing the subscriber file.
 3. A paging networkin accordance with claim 2, wherein:the digits of the identificationnumber identify the lata switching means having jurisdiction over alocal switching means containing the subscriber file storing areadestinations in the network where pages are to be transmitted to thepaging receiver identified by the identification number accompanying therequest for placing a page.
 4. A paging network in accordance with claim3, wherein:each lata switching means has a table storing identificationnumbers of all of the subscribers of each of the local switching meansunder the jurisdiction of the lata switching means with the tablepermitting the local switching means under the jurisdiction of the lataswitching means in which each subscriber's file is located to bedetermined by matching the identification number of the request forplacing a page with an identification number in the table.
 5. A pagingnetwork in accordance with claim 4, wherein:each local switching meanshas processing means which processes each received request for placing apage by matching the identification number contained in the request forplacing a page with a subscriber identification number stored in thelocal switching means and which adds at least one area destination inthe network to the page to form a corresponding number of pages andtransmits the corresponding number of pages back to the lata switchingmeans having jurisdiction over the local switching means and, if localservice is specified in the subscriber file, transmits the page to alocal paging service coupled to the local switching means for broadcast.6. A paging network in accordance with claim 5, wherein:the subscriberfile of each subscriber stores service options which a subscriber mayselect and each request for placing a page has a command added theretoby the processing means which is chosen in correlation with a storedservice option to produce a page comprises of the command and at leastone character.
 7. A paging network in accordance with claim 2,wherein:the stored areas in the subscriber file are each telephone areacodes.
 8. A paging network in accordance with claim 2 wherein:each lataswitching means adds a geographically descriptive number of the lataswitching means receiving the non-long distance telephone callcontaining a request for placing a page called to the lata switchingmeans prior to transmission to another switching means.
 9. A pagingnetwork in accordance with claim 8 wherein:the geographicallydescriptive number of the lata switching means receiving the non-longdistance telephone call precedes the identification number of the page.10. A paging network in accordance with claim 8 wherein:each lataswitching means adds a geographically descriptive number of the lataswitching means receiving the non-long distance telephone callcontaining the request for modifying a subscriber file to each requestfor modifying a subscriber file prior to transmission to anotherswitching means.
 11. A paging network in accordance with claim 10wherein:the geographically descriptive number of the lata switchingmeans receiving the request for modifying subscriber file precedes theidentification number of the page.
 12. A paging network transmittingpages to paging receivers identified by an identification numberaccompanying a page and permitting requests for modifying a subscriberfile of a subscriber to be made throughout a network in a plurality ofgeographic areas without the placing of a long distance phone call, eachrequest for modifying including an identification number of a subscriberfile is to be modified and the subscriber's paging receiver to receivepages with specified digits of the identification number of thesubscriber identifying an area within the paging network where thesubscriber file storing information pertaining to the subscriber isstored comprising:(a) a plurality of lata switching means, each lataswitching means being located in a separate telephone area code andincluding a telephone port for receiving telephone calls requestingmodification of a subscriber file located within the network placedwithin the area code including the lata switching means without a longdistance telephone call; (b) a plurality of local switching means, eachlocal switching means being under the jurisdiction of a single lataswitching means and coupled to a local paging service which broadcastspages with each lata switching means having at least one local switchingmeans under the jurisdiction of the lata switching means; (c) means,coupling the lata switching means together in the network, fortransmitting requests for modifying a subscriber file between lataswitching means; (d) each lata switching means processing the specifieddigits of all requests for modifying a subscriber file received by anon-long distance telephone call to the lata switching means and fromthe means coupling the lata switching means together to determine if thespecified digits of the request for modifying a subscriber file matchdigits identifying the lata switching means and transmitting thoserequests for modifying a subscriber file which have specified digitsthat identify the lata switching means to a local switching means underjurisdiction of the lata switching means which stores a subscriberidentification number accompanying the request for modifying andtransmitting all other requests for modifying to the means fortransmitting requests for transmission to another lata switching means;(e) the means for transmitting the requests for modifying transmittingthe requests for modifying a subscriber file to a lata switching meanswhich is identified with the specified digits of the identificationnumber; and (f) the local switching means, having a subscriber filecontaining an identification number of a subscriber matching theidentification number contained in the request for modifying, modifyingthe subscriber file in accordance with the information contained in therequest for modifying.
 13. A paging network in accordance with claim 12wherein:the subscriber file of each subscriber is stored by a singlelocal switching means.
 14. A paging network in accordance with claim 13,wherein:the digits of the identification number accompanying the pageidentify the lata switching means having jurisdiction over the localswitching means containing the subscriber file.
 15. A paging network inaccordance with claim 14, wherein:each lata switching means has a tablestoring identification numbers of all of the subscribers of each of thelocal switching means under the jurisdiction of the lata switching meanswith the table permitting the particular local switching means under thejurisdiction of the lata switching means in which each subscriber fileis located to be determined by matching the identification number of therequest for modifying a subscriber file with an identification number inthe table.
 16. A paging network in accordance with claim 15,wherein:each local switching means has processing means which processeseach received request for modifying a subscriber file by matching theidentification number contained in the request for modifying asubscriber file with a subscriber number in the local switching meansand adds information to the matched subscriber file contained within therequest for modifying.
 17. In paging network providing paging service ina geographical area covering a plurality of telephone area codes withthe network having a plurality of switches disposed at differentlocations within the geographical area of the network which are linkedtogether by a transmission system for transmitting pages and requestsfor placing pages with at least one switch being disposed in each areacode and permitting requests for placing pages to be made throughout thenetwork without the placing of a long distance telephone call, eachrequest for placing a page including an identification number of asubscriber of a paging service coupled to the network and a pagingreceiver to receive the requested page with specified digits of theidentification number identifying a switch within the paging networkstoring a location of a switch where a subscriber file storesinformation pertaining to the subscriber including any areas containingswitches in the network where pages are to be transmitted and asubscriber identification number, a method comprising:(a) each switchingreceiving a request for placing a page processes the specified digits ofthe identification number included with the request to determine if thespecified digits of the request match digits identifying the switch andfor those requests which have specified digits that identify the switchthe identified switch initiates the generation of a page by transmissionof the request for placing a page to the switch where a subscriber filestoring the identification number is located; and (b) if the specifieddigits of the request do not identify the switch, the transmissionsystem transmits the request for placing a page to another switch whichis identified with the specified digits of the identification number.18. A method in accordance with claim 17 wherein:the subscriber file ofeach subscriber is stored at a single switch in the network.
 19. Amethod in accordance with claim 17 wherein:each switch, which receivesthe request for placing the page from a switch initiating the generationof a page, interrogates a subscriber file containing an identificationnumber matching the identification number contained in the request toplace a page, and forms at least one page with each page being forbroadcast by a local paging service or within at least one area codewithin the network.
 20. A method in accordance with claim 19wherein:each switch initiating generation of a page is a lata switch;and each switch, which receives the request for placing a page from aswitch initiating the generation of a page, is a local switch.
 21. Amethod in accordance with claim 19 wherein:the subscriber file of eachsubscriber is stored at a single switch in the network.
 22. A method inaccordance with claim 20 wherein:the subscriber file of each subscriberis stored at a single switch in the network.
 23. A method in accordancewith claim 17 wherein:the another switch receiving the request forplacing a page initiates the generation of a page by transmission of therequest for placing a page to the switch where a subscriber file storingthe identification number is located.
 24. A method in accordance withclaim 23 wherein:the subscriber file of each subscriber is stored at asingle switch in the network.
 25. A method in accordance with claim 23wherein:each switch, which receives a request for placing a page fromthe another switch initiating the generation of a page, interrogates asubscriber file containing an identification number matching theidentification number contained in the request to place a page, andforms at least one page with each page being for broadcast by a localpaging service or at least within an area code within the network.
 26. Amethod in accordance with claim 25 wherein:the subscriber file of eachsubscriber is stored at a single switch in the network.